When did that happen??

OK......so, I blinked and now Mason is turbo-charged and crawling around everywhere up on his knees. Since when did he drop the army crawl??!?!? AND not only that, but he is starting to pull up on everything....the coffee table (source of many bumps on his head), his toys, his changing table, my pant legs, etc., etc., etc.!!! He loves to stand while someone holds his hands. He's wobbly, but he's standing! What a difference a weekend makes. Where did my baby go??? I think I'll have more trouble with his turning one than I did with my turning twenty five for the sixth time!