Hello folks. Back again. I'd like to call a young person "Little Sponge" or "My Little Sponge", as in he is a good student who sucks up everything he's taught. It's meant affectionately. The child is male, primary school age, and small for his years (hence the diminutive). If there's a better word than sponge, I'm open to suggestions. Can you help me get it right? Thanks as always.