Why do I still have a high tolerance?

So, after one of my parents passed away, I got into drinking almost every day. My choice of alcohol was vodka. This went on for about a year and a half until one day like a light switch, I just stopped drinking. No reason why, just didn’t want it anymore. This was about 6 mths ago. Since then I’ll have an occasional drink when I go out with friends, but if I order anything with vodka now, I don’t feel any effects of it. It is if I drank water in a way.