The lighter side of ADHD
Is this really an ADHD thing? I'm not diagnosed but I do this constantly. Visiting parents in the evening? Day gone. Errands that will only take me an hour? Day is gone so I guess I'll play video games or something I can hop out of at any time since my day is over.
For me at least, it's that I can't do anything of substance until the scheduled thing is over. I can't even start the video game while waiting because I'm worried I'll get too engrossed and forget about the thing I have to go to later.