We don't know exactly what causes stutter. The science simply isn't done yet. :) We do know, however, that stutter varies a lot. Seems like what you're experiencing. The important thing is to be aware of it. You might also benefit from notifying those around you. - --- *I see /u/PreviousFix6 has used my comment as an occasion to spout more of their usual garbage in here. Please, nobody pay attention to it. It's nonsense, and I wish they'd be removed from this place, but for some reason, they're still around. Just ignore them.*