A door that was locked at 17 might open at 24. Keep the key, try it again later.

A closed door reports on one moment, not on a permanent arrangement. Circumstances shift, the people deciding move on, and the version of you knocking is not the same version a few years from now. Treating an old refusal as a standing rule is how people abandon things that were only ever postponed.

Write down what you were told no about and set a date years out to look again. In the meantime keep the part of yourself that wanted it in some kind of practice. Try the handle again when the time comes, since nobody is stopping you from checking.