What's the Name of That Book??? discussion

I can't remember much more about that book, except that it was about the protagonist's impulse to collect things.
I seem to associate it with a Germanic/ Austrian/ Eastern European author, and to remember a cover with dark brown.

Did he have specific collections (seashells, stamps, Hummel figurines etc.) or did he collect everything, like a hoarder?
When was it published or when did you read it?
How old was the character?
Single, married, kids?
Author's gender?

Any other details you remember could be helpful.

Caroline, around what year did you read this book? This will help us narrow down the search.

Can you give examples of what he liked to collect?

The Germanic/ Austrian/ Eastern European author thing, in the context of 'collecting' made me think of Tibor Fischer (although actually he is British) and his book The Collector Collector but the protagonist isn't a man (!)