You have them, all the time. And some part of you might want to hold onto them, to save them for later when you’re ‘better’. Or you might think that one idea is the best idea you’ll ever have, and you might feel anxious to get it right. Well, you’ll have a hundred other ideas, and they’ll be even better. Your writing from several years ago isn’t as good as it is now, and so your ideas in a few years will be better.
Use up those ideas as you get them, it’s exercise for your brain to think up more!