Hello, Object Permanence!

I've been suspecting for a couple of weeks now that Clark has the object permanence thing going on, but as of tonight I'm sure of it. Clark was sitting in his swing, playing with a toy elephant. Every time he'd drop it, he would start to cry. I'd go and pick it back up and hand Clark the toy, and he'd stop crying. Over and over again. Out of sight, out of mind? Not anymore.