That is as true for any flu - or indeed any disease - as it is for COVID-19. There are many diseases out there and most people don't know very much about any of them regarding what a 2nd infection might do. It isn't a reason for them to behave any differently to how they behaved in 2019.
How common is that? I know there have been a few cases where it's believed to happen, but similarly there are some cases of people getting chicken pox more than once. With chickenpox, that's rare enough that chicken pox is generally considered something that you only get once, but it does happen.
That doesn't answer my question though. What does the data actually say about the covid reinfection rate? I've heard of anecdotes, but haven't seen any numbers.
It could impact them differently if they contract it again.