Learn to forget?

How do you actually do that? You need to know how to forget, and to know, you need to remember. So in order to remember, you can't really forget it. So how do you learn to forget? Once you learn how to forget, you have to forget how to forget. If not, then you have learn nothing, either way. If you remember how to forget, you didn't actually learn to forget. If you forget how to forget, then you have learned, up to the point you forget how to. Oh boy, this is one paradox that happens due to the lack of definition. Well, all I can say is, no one can really choose to forget.