Is it normal for sexuality to change through years?

I thought I was straight up until I turned 21. I fell for a girl and preferred girls for over 3 years and now suddenly I like a guy who liked me back and I prefer men again??? Am I just straight who went through a phase? Or is it possible that I would start liking women again? What triggers it? It’s confusing.. Anyone experienced this? The weird thing is when I preferred women, I completely forgot what it’s like to love and crave being with a man. Now, it’s like I’m going through puberty again and I am horny for d*ck. Marrying a man doesn’t sound bad at all. Men are appearing more attractive. A few years ago, I wouldn’t notice them at all.. Is this normal? Has anyone experienced this before? It’s like a « girl love » switch was turned off, on, then off again.