Unsinkable

Dillon: Mom, what’s 4-D mean?
Me: Um… Well, you know what two-dimensional and three-dimensional are, right? I don’t think anything is 4-D.
Dillon: No. Mom. The fourth dimension is time.
Me: [mental headdesk] Right. So why did you ask me what something was if you already knew the answer?
Dillon: Well, I saw something at the movie theater and I wanted to know if it was a real thing or just advertisers wanting to charge people more for stuff.
Me: Oh. The second one.