Join the club. One of mine is addicted to fetch and stares at me if I dont indulge him, and he insists on fetching at all times, other than brief breaks for eating and sleeping
This is different behavior from my other two who are/were never addicted to fetching. Lately, he also has been happy to play tug-of-war between tossing his rope or whatever. That is a nice change, but I think he'd fetch with a little tug of war in between forever.
He is also most interested in motion and loves to bark at anything outside he is unfamiliar with or wants to chase down, like squirrels or birds. I think these traits are related.