When you're with someone 24/7 for a vacation, you tend to run out of things to say to each other.
I'll fully admit that while we're queued up, I'll be on facebook, twitter,
instagram, my work email, or *gasp* even here on the DIS. Yes, the lines are themed, but when it's 95 degrees out and you're in a 20 minute line... well, there's only so much to look at. It killed me, I posted while I was on my trip about a situation in the parks that surprised me, and people came out of the woodworks to bash me for posting whilst on my vacation. It was 11:30 at night. I was on the boat back to my resort. My family had already gone back... but shame on me for not enjoying the scenic boat ride in the dark.
My DH and I both have ADHD, and one of the main reasons we enjoy our vacations because it means a drug holiday for us we either don't take our meds, or we only take a half dose to give our bodies a break. If we didn't have something to occupy us in line... well, I'd feel bad for anyone in front of or behind us.