It’s always the same when he regenerates, everything’s new and unfamiliar; arms, legs, body, hair, all longer or shorter than he’s accustomed to. His sense of taste changes, favourite foods taste awful and things he hated before are suddenly delicious. His nose smells differently, his hands don’t work right, his eyesight changes... You’d think regeneration would mean 20-20 vision as standard, but it seldom does.
He has to get used to a new way of walking, a new perspective on everything, but as difficult as all that is, the worst thing is always the teeth. They keep biting his tongue!