When Did I Become 'Mom'?

Yesterday, Thomas had the day off from school for Columbus Day, but Hudson had Mother's Day Out. So Thomas and I had a (rare!) special day with just he and I. It was really fun. We went to several stores looking for birthday party ideas and I took him up to Vulcan Park. (I had flashbacks to a girl scout trip to Birmingham!). Vulcan Park has been renovated, and it is really well done and has beautiful views of the city. Thomas had a great time (which was the whole point anyway)! While we were at Vulcan, I noticed he was calling me 'Mom.' At the beginning of his young life, I was Mama, and then for the longest time I was Mommy. And now MOM? It just sounds so grown-up. He's not even 4 yet...