For many years I used the same name. In spite of being short and pronounceable with no numbers it turned out to be quite unique. Even after all these years I can search that name and come up with some of my posts and comments. I stopped using it over ten years ago. As near as I can tell only one other person ever had it as a username.
Now I just pick something random when the question arises during registration. I only have three accounts so it's not hard to remember. Passwords are handled by a password manager.
My current name is actually a different spelling of the first name I had on Lemmy. But, I made a dumb mistake and lost the password, so I made this account.