Milestones pass you buy like a warm summer day ... or a warm winter day

The boy opened his mouth to show me the damage.

"Yep. That tooth's gone, alright."

What he showed me -- mouth agape, chapped lips stretched gingerly around his choppers -- was a row of otherwise normal-looking teeth interrupted by a red crater. After he poked at it gently with his tongue, I could see what was left, and the tip of the new tooth coming in.

I remember him telling me the other day that his tooth was loose, and then replying to him, "Damn, boy! How many teeth you got in there!? I've never known anyone who has lost as many teeth as you have!"

"This is my last one," he said.

"Oh ..."

And, as usual, this is when my heart began to beat a little faster, my anxiety crept up a little, and I just got a little bit sad.

This was a milestone. All those days helping yank dangling teeth from mouths, of instructing them on how best to go about preparing teeth for the tooth fairy -- that's all over now. In one final act of rebellion by the boy's mouth, the new tooth kicked the little guy out. And just like that, a wonderful perk of having kids had finally run its course.

I love watching my kids grow up. And every day they spend here, they get so much more interesting and fun to hang out with. But there's a built-in dilemma with that: as they get older and more interesting, they get one step closer to leaving. And as many times as I try to not see it in those terms (it's hard a guy), I simply can't help it. With each grade they ascend to in school, they're closer to leaving, with each set of birthday candles they blow out, they're close to leaving. And now, with this last tooth out the door, I can't help but feel the boy and his older sister are just that much closer to leaving.

They've each lost many teeth over the years. They've lost teeth in DisneyWorld, Duluth and at school. The girl lost one while we were cutting down a Christmas tree at Little's Tree Farm some years ago. And once, while one of them was at the dentist and had a semi-loose tooth, Dr. Keith Flack did us a solid and, after properly numbing the area, pulled it out.

So now it's over. No more teeth under pillows, no more watching a kid's face grimace as they wiggle a tiny piece of bone that can cause so much pain.

What made this last one hard for me wasn't so much that it was the last, but that I wasn't there for it. And as I looked at that hole in his mouth, I tried to remember when was the last tooth I witnessed come out of his mouth.

And I couldn't.