T.D.
Some of it may just be fascination with the process. But I did find that my kids had a hard time at this age wiping. I bought the moist wipes that are flushable for both my kids at this time and they did a much better job. Handling toilet paper with poop can be a tough task for little guys at this age. They can't actually see what they are doing either which doesn't help.
The moist wipes really helped alot.