Absent-minded: when one is too busy thinking about something else to pay attention to reality
going on around him or other peripheral
issues like weather
, oncoming vehicles and so on.
Example: I was co-lecturing a course for the first time. The day of the last lecture had come. I was still rushing to finish the slides 'til late the night before. Anyway, I wake up, put on my shoes (around 9am) and drive to the University to just put the finishing to the slides ... lecture's at 6pm. I work through the day, with a slight pain in my foot, but ignore it ... must finish lecture.
I give the lecture, it goes well. Last lecture, so I get a standing ovation. Then one of the students in the front row says "Mate! What's up with the shoes?" I look down and discover that I'm wearing shoes from different pairs ... one black, one white. "Oh bugger," I respond.
I point this out to my co-lecturer, who says "It's a bad omen! You're never going to leave academe!" "What do you mean?" I say, "Well, only an academic could be so absent-minded".
Note the subtlety here. Putting on shoes from different pairs and getting caught is just embarassing. However, getting through the whole day without noticing that this is the case is absent-minded.