What Giacomo said about Spencer

Yesterday, out of the blue, Giacomo says:

"Spencer is a big, big dad! And he can break wooden chairs, because he has a big tushie and a big heart!!"

and Spencer did break a wooden chair a few years ago at my moms house when he sat on it! But Giacomo was just a baby then! How did he remember that?! Andy why would he say that now?!?!?