Losing my mind

Lately I've been thinking that the closer I get to a PhD, I am starting lose common sense and the ability to function well in the real world. Yesterday I was in the grocery store with a friend, who is also getting her PhD, in Psychology, and we decided to use the self checkout line. We couldn't figure out how to weigh tomatoes so we had to get the guy from a register to help us! Then the other day, I left my place with the single intention of going to the pharmacy, which is all the way down the street 4 blocks from my apartment. On the way there I was making a list of things I needed in my head, then started daydreaming, and woke up 2 blocks past the pharmacy. What is going on? Isn't more schooling supposed to teach people to be better at life? Not graduate school I guess. We're learning such specific information and techniques that it's pushing out the real important things from our brains, like how to weigh potatoes and get to the pharmacy in a straight line.