Grade yourself with no curve and no filter once a month. Nobody else has to see the report card.

An honest private assessment is possible in a way that a public one never is. Nothing is being defended, nobody is watching, and there is no reason to adjust the result, which makes it the only version likely to be accurate. The point is not to be harsh with yourself. It is to have one place where the account is not managed.

Set aside twenty minutes once a month. Write what went well, what did not, and one thing you would change. Nobody else reads it, which is precisely what lets you write the true version.