Why is he chewing gum at 21 months?

So I get home from work to discover that Julian is chewing gum. Yes, you heard me right, CHEWING it! My mom is notorious for always chewing gum and has taught her sweet boy how to follow in her footsteps. While I do not condone this behavior I was kinda impressed at how he kept the gum in his mouth and never ate it. How many pieces of gum did he eat prior to learning how to chew it is anyone's guess? :-/