We have some dear friends who are in the states on furlough from their mission work. They have a son named Caleb who Seth has enjoyed playing with. Caleb is about five years older than Seth. That doesn't seem like a lot, but Seth is only three and Caleb is eight.
My sister took Seth and Caleb to the park one day. The entire afternoon, Seth talked about Caleb!
Now, Caleb lives with us. That is, imaginary Caleb.
Caleb takes naps with Seth, goes to work on occasion, eats lunch with us, and keeps Seth company.
Caleb (the real one) is the first person, outside of family, that has made such an impression on Seth. It is really neat to watch!