Welcome to toddlerhood, Luke!
He turned 1 a few months ago & "officially" became a toddler, but it hasn't been until this past week when he has fully realized it!
I believe that the official beginning of toddlerhood is when they learn the word "NO!" Toddlers love this word & use it quite often for everything, sometimes even when they mean yes.
So, Congratulations son! You are now an official toddler in my eyes, since you have began saying this wonderful word now (although he only says it in a singsongy way thus far) & as your mother, I fully realize that we have really only just begun!