I also know people who get it over and over again. All they do is go to work and then go home. They see a few people on the weekend but mostly just their grandchildren. I used to blame them for it (not out loud of course) but now I just think they are just more susceptible to covid than most others.
Either way, I hope you fell better soon. Hopefully, after a few months, you can get a booster which may raise your immunity.