Julie LOL at the fingerpainting

Does anyone else leave their bub to amuse themselves for, like half and hour to an hour at a time? Flynn just crawls around his room playing with stuff or plays int he lounge while I type here or do housework. I kinda feel like I should be "interacting" with him. Or am I being paranoid? Should I just be thankful he self-amuses? Maybe this is the "grown up" manifestation of my early fear that he was autistic because he so rarely cried LOL!!