By far the easiest explanation for the popularity of the Graham Greene novel Travels With My Aunt is to site Greene's already well established following. However, it must be recognized that Travels represents Greene's first top ten hit, garnering the number nine spot in 1970, according to Cader Books (from which the information to compile this data base was obtained), written almost forty years after his first big commercial success, Stamboul Train (1932). There are fourteen novels in between, many of which were critically better received-- three, in particular, generally thought of as his best work, Brighton Rock (1938), The Power and the Glory(1940), and The Heart of the Matter(1948). Further underlining the uniqueness of Travels success is that only one other of his novels would follow in the top ten. In 1973 Greene's next published, The Honorary Consul, placed tenth, suggesting a coat-tail effect.

One can relatively safely assume that if it wasn't the critics favorite Travels was a little less high-brow than some of Greene's other works, and perhaps therefore more accessible, more desirable to the public. But this is not Greene's first so-called accessible novel. He is, in fact, known for a particular kind of genre, the entertainment, a term which he coined, and which carries obvious connotations when opposed to his other more weighty category, the novel. Stamboul Train, already mentioned, is said to belong to the former, for example, although the distinction is often difficult to make. Greene, himself, stated that it was merely a question of length, an entertainment being shorter. As this relatively arbitrary difference suggests his works often blur the lines between genres, as he as an author skirts the line between canonical/serious and popular/best-selling, combining elements of many different kinds of literature. Travels does, however, seem to have a fun element unique to it, which Greene himself admits.
I'd embarked on this adventure for my amusement, with no notion of what might happened the next day. (O'Prey, 122)

Travels is a particularly good example of Graham's synthesizing several different ideas into a unified whole.
A number of ideas I expected to use in short stories became recollections of old Augusta. I was surprised that they all cohered into a logical sequence, and that the novel became a finished product, for I'd been regarding it more as an exercise based on the free association of ideas... (O'Prey, 122)
The existence of so many different lines have, in fact, precipitated criticism of the novel as episodic. The truth in this objection is remedied by the extraordinary interest, having an effect like glue, which the character of Aunt Augusta provides.
"[T]he author indulges himself grandly, not sparing extravagance and coincidence... but the weakness of the form, the risk of complete disintegration... is avoided because a unifying principle of interest has been substituted which is maintained through all the episodes." (Sharrock, 261)
The episodic nature may even be considered a strength, for many of those episodes hark back to Greene's earlier works. Travels is in effect a trip down memory lane for the Greene loyalist.
"[T]his book is chiefly a joke on himself, for the benefit of his faithful readers." (Thompson)
Names, places, and Greene conventions are repeated, the most obvious being Henry and Augusta's trip to Brighton, and the ride on the Orient Express, which refer to two of his most popular novels already mentioned.
Some critics have found in the book [Travels] a kind of resumé of my literary career- a scene in Brighton, the journey on the Orient Express... (?)
Perhaps even more interesting is that Travels is a trip down memory lane for Greene, himself, the author and the man. There are several references to authorship, which proved quite revealing, as well as what appear to be more personal comments. Greene lead a very interesting, somewhat scandalous life and was notoriously stand-offish in interviews, so that this type of candidness might prove very appealing to the public's curiosity. All of this combined makes for a book that anyone who has ever loved a Greene novel does not want to miss.

But there must be more to it than that, because surely if it were merely up to Greene fans all his novels would sell so well. There are two plausible and interconnected reasons for the expanded readership. Firstly, few people speak about Travels without revealing a partiality for the character of Aunt Augusta. Giving birth to this flamboyant old lady is Graham's masterpiece as far as the public is concerned. Secondly, the ideas espoused through Augusta's person are anti-traditional, stressing relative morality. This couldn't help, but appeal to the 69'/70' crowd. Henry's journey into Aunt Augusta's world from the land of dahlia cultivation is easily interpreted as one from the tame, middle-class quality of the 50's to the turmoil and excitement of the 60's. Lacking demographic data as a basis of theorizing further is a handicap. Nevertheless, one might surmise that such progressive, shocking ideas coming from someone of a decidedly older generation must have proved amusing to the young protesters who 'trusted no one over thirty'.

One can't help reading Greene in the personage of Aunt Augusta. Is it possible that we, the readers, are then several Henrys? Greene does seem to be trying to jerk us out of a rut, a rut decidedly middle-class and suburban. There are few monsters to fear in a gated community. The real fear is growing up to live in one.
Henry: "I was afraid of burglars and Indian thugs and snakes and fires and Jack the Ripper, when I should have been afraid of thirty years in a bank and a take-over bid and a premature retirement and the Deuil du Roy Albert." (163)
An even worse fate is growing up to have a hobby. Thus the several types of flowers Henry cultivates are ironically named, as if they provide the excitement those names suggest: "Maître Roger, Cheerio, Arabian Night, Black Flash, Bacchus, Ben Hurs". In particular Greene rails against the attitude of the sanctimonious, making a faithful wife seem ridiculous, and even a perfectly forgiving wife all the more horrendous.
Aunt Augusta: "I despise no one. Regret your own actions, if you like that kind of wallowing self-pity, but never, never despise. Never presume yours is a better morality..." (111).

But rejection of conventional morality is merely the accompanying step to an even greater leap of faith, the rejection of safety. Literary big wigs had been lamenting the loss of danger for some time before Greene, and this is perhaps where Travels takes on a more serious air. For despite its humor, the novel's story line as well as its characters have a dark side to them, an element seldom absent from Greene's work. It is not exactly a happy ending, although Henry escapes boredom. It is the sense of stagnation in a world where living to a ripe old age is a relatively sure thing that had become his "open prison". The 'kids' may have been protesting for peace in 69', but you have to ask yourself if that's truly what they desired in the total sense. For, those protesters very much enjoyed the rebellion, enjoyed fighting for a cause. If they really had wanted peace for themselves they would have stayed in the suburbs. Many baby-boomers talk of the era as the best time of their lives. They had felt restricted before the turmoil. In the mist of the chaos and the struggle they felt vital and free. So very much like the hippie generation, although much less idealistic, the solution for Aunt Augusta is disobedience and danger. It is the elixir of life, giving purpose and vitality.
Henry: "Was the secret of lasting youth known only to the criminal mind?" (169).