They Say Travel Broadens The Mind

This was an attempt to quickly explain the concept of time travel to my (then) seven-year-old, after watching an episode of Doctor Who. That stick figure on the left represents him, moving from today, on into tomorrow, he must have had a Doctor's Appointment coming up in the next week or so, and then on to his birthday, all in a straight line, in one direction. But what if, I asked him, he could move back and forth between those events? He drew himself a little TARDIS.

I think he understood the idea well enough to send himself a present — into the future! (That's him opening it, between "Christmas" and what I'm sure is supposed to be "Hanukkah.")