In my twenties I read a fair bit of Hermann Hesse. All the main ones, The Glass Bead Game, Steppenwolf, Narcissus and Goldmund and several others. I think I re-read most of them in my thirties and, like the first time, I really only understood them as a story rather than anything deeper.
I read a few of E M Forster and George Orwell. I loved Orwell’s Keep The Aspidistra Flying – the cover evokes so many memories. There was a phase of Kingsley Amis – Take a Girl Like You, Lucky Jim, One Fat Englishman.
I had a long phase of reading American crime novels – the Travis McGee books of John D MacDonald and the Lew Archer books of Ross Macdonald. The Travis McGee series all had a colour in the title and had some great covers. I regret letting them go.
Then came a series of psychological thrillers by Ruth Rendell. I vaguely recall them as being about rather inadequate / disturbed people (mainly men?), but they were good.
I would read computer books and manuals – it was the industry I was in after all. In between there was sociological stuff – Herbert Marcuse’s One-Dimensional Man; J K Galbraith ‘s The Affluent Society, and some politics stuff. Novels by John Fowles – The Magus and Luke Rhinehart’s The Dice Man, were mixed up in there somewhere. There’s lots more that may eventually spring to mind.