Anecdotally, whenever I go swimming with my kids in the summer, and I don't put sunscreen on right away, but let myself get some intense direct sun, I feel good and sleep really well that night. As long as I don't let myself get in a red, sunburn situation.
I typically do the same thing. I only wear sunscreen if I am planning on being in direct sun for an extended period of time where I can't easily get back in the shade. The more you're able to build up a base tan the less you need it to avoid a burn at least.
(It's largely irrelevant to myself, I pretty much burn immediately and don't / can't really tan, but my wife and her family tan well).