This is a stereotype, and there’s probably some truth to it, but I think it depends. I’m highly intelligent and educated myself, and there’s some things that I’m absent minded about and other things that I’m not. The thing is, no matter how intelligent one is, there’s a limited amount of attention one has, which may be more or less for different people, and it has to be divided between various things. Someone who is highly intelligent can easily have that level of discipline too.
Speaking for myself, I think I used to be a lot more absent minded than I am, and I think my intelligence is a large reason why, but not because higher intelligence means lower attention. Rather, I think a lot of people learn about how to pay attention and retain information and not get distracted as part of their education. If you have to study, take notes, remember facts, and have good time management skills to do well in school, you learn those lessons at a younger age. I coasted through most of my education with no effort and I never really learned those skills. As a result, when it came down to times when I needed to discipline myself with time management, routine, all that sort of stuff, I just plain sucked at it. I’ve gotten a lot better about it, but probably by going a bit too far in the other direction.
I also think people who tend to be very heady or idealistic will have these problems too. At least for me, I’ll sort of get lost thinking about things and not really focusing on what’s going on. Having a solid routine is good for managing this, but this also means that if, for whatever reason, I put my wallet down in a different spot, I can easily miss it in my routine and forget it. To some extent, there’s the idea that more intelligent and educated people might be more likely to be like this. If that’s true, it’s probably just because of extended exposure to academia.
Either way, I think this is mostly just confirmation bias. We recognize the smart people like this, but when we see less intelligent people, rather than thinking they’re dumb and absentminded, we just lump it all together as dumb.