And depending on the person it can also change depending on diet and mixing microbiomes. Back when I lived with roommates my frequency changed based on who I lived with to some extent, matching closer to their frequency without changing diet (since I was weight training my diet was controlled and I didn’t eat their food).

Now living permanently with a spouse it has settled on a higher frequency than I remember before moving out on my own. Weird stuff.

That's wild, my frequency has remained pretty consistent through my life, although I did have a couple years where somehow one of the days each week I'd do it would always be Monday, and I never had any explanation for why that was the case.