development of a child

I made a new and interesting experience with my 3yr old son last Sunday.
I was pretty strict and harsh and serious with him (o, how cruel can a father be?! (but self-critical as well!!!)), and he showed pretty good "taking qualities" (german: Nehmerqualitäten), but he still started to show, how much my appreciation means to him: he showed us, he is able to pronounce words with "R" properly now in German, "rot, rot, rot!" he shouted all of a sudden (that's the colour "red" in English), because until very recently he (as a Portuguese native speaker) used to pronounce it "bot", and it took me endless repetitions pronouncing it properly to him, that looked quite unsuccessful to me -- until last weekend. I am very, very touched. I am very proud of him.

P.S. Suggestions for better English always appreciated.