Third son potty trains himself?!

It was almost bathtime, so I left Will's diaper off after a diaper change. We heard him in the bathroom and a few minutes later he came and said, "potty" several times. So, I asked him if he needed to go potty and he replied, "uh-huh" and bobbed his little head up and down. Half-heartedly I said, "ok" - can you hear the long drawn-out-do-we-have-to syllables? :) So, I walked with him to the potty and there he had already placed his little potty seat on the toilet - hmmm, I realized he was serious - so I sat him down. Yep, he immediately started to go potty! The little fella knew exactly what he was doing. The whole family came to cheer and applaud - he was smiling from ear to ear and clapping for himself - so cute! His reward was that he got to flush the potty! Do third sons usually just train themselves like this??? This could be great...