Old letters often apologize for bad handwriting. Notice how often people apologize for things nobody minded.

People spend a lot of their lives apologising for things nobody had noticed. Messy handwriting, a tidy-enough room, the sound of their own voice, taking up thirty seconds of somebody’s time: the apology is usually the first time the other person has even considered it a problem. It comes from standing too close to yourself.

Catch one of yours this week and simply leave it out. Hand the work in without the sentence about how bad it is, ask the question without saying sorry first, and watch what happens, which is nothing. Then notice when somebody else does it, and tell them plainly that it was fine.