When Naomi Rivka was a baby, maybe a year and a bit, and I was first signing with her, YM (then 10ish) was taking the deaf bus. Not a euphemism: he was going to school every day on one of those little school buses that "special" kids take because his school was close to the Toronto School for the Deaf (fingerspell it! "TSD") and so he was learning a bit of sign as well as passing some pretty rude notes plus gestures to the kid he sat next to.
Anyway, he was happy when he found out she was learning sign, and I came into the room once to find him talking to her. He'd use a sign he knew, and then, when came to a concept that was longer or more complicated than he could communicate, carefully fingerspell the missing word.
In his world, I'm sure it made perfect sense.