Babies grow fast.

That point seems pretty apparent, but when you’re around your daughter every day, like I am, it can sometimes be difficult to notice.

“Is she getting bigger?” her mother asked on a recent day. She’s around our daughter more than I am, so I forgave her for posing such an obvious question. For me, it seems like every time I go to work my little girl gains a pound.

People tried to explain this growth spurt to me back all those many months back, when my kiddo was just a red-faced, shriveled-up newborn. I had heard that babies triple their birth weight in the first year. But it’s hard to comprehend until you actually experience it.

After about the sixth month, things just took off: Eating. Sitting up. Crawling. In fact, my daughter is already twice as big as she was in this photo and happily married (well, not “in fact.”)

Accompanying this growth spurt was a burst in the number of activities she could do. One recent morning I awoke to find her awake and standing up in her crib, staring back at me. Another day, she was sitting on the floor in front of me, and when I looked away for a brief moment she was on the other side of the room (Did she just teleport over there?) It’s fair to say we no longer have anything on the ground that can be tipped over.

As a new parent, you quickly find out that much of the advice you get from friends and family members is true. Like when they tell you to appreciate the time when your baby can’t get around on her own. Well, that time for me has officially ended.

At first, my baby would sit in her crib or car seat and cry if she was hungry or needed her diaper changed. Now, if she needs something, she’ll crawl up to me, pull herself up by my pant leg and stand in front of me, yelling, until I meet her demand.

And until you have a baby, you’ll never know how fast your reflexes truly are. Say you and your little one are sitting on the couch together: You might divert your attention elsewhere momentarily, but as soon as she gets too close to the edge you will scoop her up with the speed of the world’s fastest pickpocket.

So if you’re the parent of a newborn, get ready for rapid-fire growth at any moment. If you have already entered that phase, you have officially given up extended periods of sitting. But look at the bright side: At least you’re no longer a couch potato. Crawling babies whip you into shape real fast.