I don't really count, about a dozen I think.
I might sound a bit pedantic, but when I do hand applied finishes, I keep a little notepad on the bench and mark down each coat as I go.

It's really easy to lose count (especially if you're over 50 y/o ) and it's hard to tell by eye if you've got 15 or 50 coats... until you sand... and then it may be too late.

With Tru Oil, I do a minimum of 24 coats. I know others that go 50, but I fall short on the patience scale there. However, I have not had a sand-through using my minimum 24. TBH, I've probably gone up to 28 because, even writing it down, I get confused and just go more.

Also IME with Tru Oil, when I start wet sanding, I'm pretty comfortable starting with a pretty fine grit like 1000-1200. Hand finishes just don't get the depth of dimples like orange peel you get from spraying things like lacquer, so there's no reason to go hard at the start.