Oh, yeah, piano 24/7 - if I didn't have a real piano I'd do the fingering on the table or in my head. Then I discovered the bass guitar, joined a bunch of bands, had a great time.
I still play piano, it keeps me sane. Nothing like a few Bach fugues to put the brain back to normal after a stressful day.
edit - my father was a jazz pianist, so there was nothing abnormal about playing piano all day at my house.