The advice you’d give your younger self is probably advice you still need.

Advice for a younger version of you is easy to produce, because you can see that situation clearly from outside it. The uncomfortable part is how much of it still applies: be less afraid of looking stupid, say the thing, start now, stop performing. You were not handed that advice late. You were handed it early and have not finished using it.

Write the one sentence you would give your fourteen-year-old self. Read it as though it arrived today, and act on it once this week.