Yes! Invincible is my favourite book of all time - but all of his books exude the same aura of unknowing and never being able to know everything, unlike with most authors.

The problem I have is recommending his books to my English-speaking friends - again, my favourite Invincible for example, has only been translated to English from German, not from its native Polish - so the translation is lacking somewhat, and there doesn't seem to be interest in producing modern translations and releases of Lem's books in English.