Nate's visit

Last week...yeah, a week behind, I know...my family came over to see my younger brother Nate while he was in town for a wedding. He moved to Pennsylvania last year for grad school, and we hadn't seen him since.
Nate is crazy.
He's in school to teach and he fits the "absent minded professor" bill nicely. For example:

He stayed overnight with us while he was in town, but "forgot" to tell us that his friend was staying, too. We do not have a spare bedroom and we only have one sofa. Someone got the floor.
He borrowed our spare house key, but when he left he put an extra key on the coffee table...the WRONG key. I do not know where this key came from but it's not ours.
We planned a brunch with him and the family, which he was excited about, and then he made plans to have breakfast with a former professor. So he had brunch and breakfast, back to back.
He traveled with just one small backpack. I assumed a change of shoes or clothes would be in there. Nope. Just his wedding gift for the bride and groom and some big heavy book.
He forgot to check into his flight early both on the way there and back.
He threw out his boarding pass when David checked in for him (Nate frustrates David, who is ultra-prepared for any situation) but I fished it out of the garbage.

Sometimes I wonder how that child is still alive, or how he went to Europe this summer and didn't get kidnapped or robbed.
Does your family have an absent minded professor?