Much of it is confidence, but it's not about 'knowing how to talk to women' (your 'game') but moreover how to engage them in conversation so they feel like they're treated as an equal. But it's also a two way thing, if you're treating them as equals (and not being scared/daunted by it) then you'll naturally be at ease, find talking easier and not fumble your words etc.
For me much of it came from meeting a good group of friends in my early 20's and just going out & having a laugh pubbing/clubbing, not really caring too much about the relationship side of things and learning how to de-stress about life & work. Prior to that 'going out' hadn't really appealed to me and the friends I had were generally not interested in the same things so we never did anything 'new'. I was very self conscious and threw myself into my work, getting overly stressed at the most basic of things, yet didn't know how to break myself out of that mindset. Some of it may have been maturity, guess I reached that a few years later than others? But by my mid 20's I'd gained confidence, not just in 'speaking to women' but of life in general. Confidence in my own abilities and confidence in my ability to make the right decisions without overly stressing about them. It didn't seem like it, but that must've changed my 'appeal' to women and I went through a few in 2-3 years when previously I'd not really had a girlfriend for 5-6 years. Had a couple of 5 year+ relationships and the current one will soon be my wife!
TLDR; Chin up, don't worry about it, sort your life out, get happy with yourself and the rest will come along!