David used the Pack N Play until he was two, long after he could climb out. It was set up in front of the bathroom door, so I could keep an eye and ear on him when I showered. For such an active baby, intent on tackling the whole world all at once, I was surprised how well he would tolerate the Pack N Play. In fact, he seemed to enjoy it. I think he liked the closed-in space, where he was protected from the greater world with all its curiosities and distractions. With boundaries, he could focus. He would look at books, push the buttons on toy phones, and work on puzzles. It never lasted more than 10 minutes, but 10 minutes is long enough to get a shower, and keeping David in the same place, wherever that be, for more than 2 minutes seemed like a miracle to me. Every minute that he was content in there (especially after he could climb out!) was a miracle to me. Finally, last summer, he stopped tolerating it at all. And that was okay. We'd had a good run, better than I ever expected, and by then I could rely on the trusty T.V. to babysit my kid for 10 minutes while I showered.
Fast forward to the present day. We recently we remembered we own a Pack N Play, which is a good thing, since that little girl of ours can be a bit of a nuisance at times with all that mobility and curiosity. (Sometimes I just need to make dinner or sweep the floor without her "help"!)
The other afternoon David noticed the Pack N Play and climbed right in. He immediately set to work stringing beads, independently. This is exactly the kind of task he doesn't normally do on his own. But it was like he had been transported into some kind of Concentration Zone. Just like in the old days. He quietly, steadily worked for, yes, 10 minutes. A miracle! (When I looked over there, I had to laugh that it was my three-year-old in the Pack N Play and my baby who was not.)
Here is David hard at work in the Pack N Play:

Here is David showing off the necklace he made with three lady bugs, one butterfly, and a turtle:
And it turns out the necklace was the perfect accessory for mowing the lawn: