I grew up with someone like this. And otherwise he was a nice likable person. And his lies were benign, but he lied almost any time you talked to him. Most people didn’t even notice, but once you did you couldn’t unsee it. A couple of times we both witnessed the same event and he would have a completely different recollection of events that favored him and I think he believed those lies himself. I think for some people it is some kind of defense mechanism.