Holden and the Bathroom

Holden does the funniest & strangest things. He is a curious little guy. I write about these things, so that when Holden is older and asks about his childhood, I can give him specific things that he said or did.
The other day Holden went pooped. In Holden style he came running out to tell me, so that I could wipe his bum. When I entered the bathroom, I knew something wasn't right. These was some pooped on the floor, so I asked Holden if he had an accident. He said "no, mom I just pooped standing up." I am not sure how many times he had tried this, but that better have been his last time. Holden and I had a long talk about how you need to poop sitting down (I REALLY hope it sunk in).
This morning Holden went pooped. yes it was sitting down. After I had wiped his bum, I told him to wash his hands. Holden has a habit of washing his hands for a long time (he really likes water). He had been in the bathroom for awhile, so I went to check on him. He had the lid on the back of the toliet off (along with the sanitzing wipes, and bum wipes that were on the back of the toliet). He was just standing there looking in, and watching the tank fill back up with water. I asked him if he had put anything in it, he said "no", then I asked if he had been playing in it, and he said "no mom I am just checking it out".
Holden makes me nervous when he is in the bathroom. I am very happy he is potty trained, but adding the bathroom to the rooms he spends time in is a little nerve racking!