Here is a story that might be helpful sometime to anyone with a boy who you thought was a grad, and then, not:
DS is 20 mo, and had been self-initiating his own pottying since 18 mo. Just when I finally thought enough time had passed that I could consider him a grad, he started to hold it for so long the pee would start to leak out. At first I thought he might have a UTI or something, and I took him in for a culture, but all was clean (they were amazed I could get a "clean catch" without a catheter- yay EC!). He would get irritated and deny deny deny if I tried to suggest he needed to pee, so I was having to (take my own advice- so tough!) just try very hard to relax and not worry about the dribbles. Then one day after a couple of weeks of this, he happened to put a rock in his little urinal, and was instantly intrigued- he peed on the rock, very pleased with himself. So I put a rock in each of his little potties. He can't resist it- he sees a rock in there, and he starts to wonder if he can hit it with his stream! He won't sit on the potties to pee anymore- he stands over them and aims at the rocks- it makes a little more overshoot mess, but at least he is not witholding pee anymore:)... and he is so happy with himself for hitting the rocks- boys will be boys- lol
"That's the way it is, if that's the way it seems to you."
"Cosi e se vi pare."