You remain legally yourself through changes that can make your own handwriting feel foreign.

The law treats you as continuous through changes that do not feel continuous from inside. Illness, age, or injury can alter your handwriting, your voice, your capacities, and the legal person persists unchanged across all of it. That constancy is a useful fiction and it is also a genuine claim about who you are.

If your own body has become unfamiliar, the persistence of your identity is not only a paperwork matter. Others still recognise you across it. And where the changes are practical, arranging help early is far easier than doing it once the change has advanced.