My girlfriend is this meme, but I am like you. Both ADHD, but whereas she loses time and ends up late to things, I end up going to things stupid-early because I'm like, "I'd just be sitting around waiting to go to [whatever I'm waiting for] anyway, so I'd rather wait extra long when I get there than wait around at home and risk being late."

On the plus side, this habit of mine has been recognized at work. When they needed someone to start coming in earlier to accommodate a student whose parent needs to be at work earlier than our usual start time, management came to me because I was always super early anyway. Now it's part of my regular work schedule to come in a half hour earlier than my coworkers, and since my schedule is shifted, I get to leave a half hour early in the afternoon. That's a win-win to me!