Why is that?

Yesterday Jeremy and I went windsurfing. Last night as I was trying to fall asleep I found myself feeling like I was floating along in the water going up and over the waves and then back and forth all over again. I remember when I was growing up in Florida, I would go swimming in the ocean (that's the kind of ocean you can actually swim in, unlike California) or after a boat ride, and I would feel the same way later in the day. You know what I'm talking about right? Why is that? I mean it's not like we were in the water for a significant amount of time. And it was a whole 8 hours later that I tired to fall asleep! Needless to say, it took me awhile to go to sleep last night! The mind is a crazy thing...