I think it's impossible to even guess what we might be doing in Heaven because the whole framework that governs our activities will be different.
On earth the primary motivation is survival. We work, we earn, we eat, we defend against, we struggle to achieve... striving is so integral to our existence that if we don't have anything to do we get bored! In Heaven there will be no struggle, no working just to survive. Our whole paradigm, our whole existence and means of perpetuation will be different.
It's like an earthworm trying to imagine flight. There is nothing to start with, no common ground that we can start from to extrapolate what we will be doing there.