Yep, I've experienced imposter syndrome. Actually, I just said something about getting over it in a post I did yesterday on becoming a freelancer.
What you said about everything being an experiment gives a great perspective. It's good to remember that's true for everyone else around us too—no matter how successful they are and how much they appear to have everything together.
To grow, we have to convince ourselves that we can do something we've never accomplished before. It's easy to feel like an imposter when we only think in terms of what we been able to do before, rather than what we're capable of as we constantly evolve. Taking some time to reflect on what used to seem impossible but has since become easy helps me see this more clearly.
RE: Negative Self Talk, Self Doubt, and Imposter Syndrome