Can I expect to learn something from every project I work on?

I realise that I can't get a piece of knowledge from each project. Of course, if you have hundreds of projects, you will build that experience, but at the beginning for small gigs, you might not learn something from a project. And that's okay, in my opinion. You don't have to learn something in each project, but you have to make sure that in the long term... I don't know. Let me just give a random number. At each three projects, you have to make sure that to learn something from there.