FWIW, the first explanation I thought of was something like "he replied to people asking for help that he was busy doing some (jigsaw) puzzles and wouldn't answer for now, thus wasting people's time by playing with his puzzles rather than answering". edit: and by puzzle I meant that kind: https://en.wikipedia.org/wiki/Jigsaw_puzzle. Puzzle in my mother tongue is the word used for jigsaw puzzles. Other puzzles are called "brain teasers".