Potty Training Horizon?

So as I was changing Isaac, he started getting a really weird look on his face and then out puffed a little fart. Then, as truly the Son of Jack, giggled. Sometimes farts mean poop. Sometimes they don't. So I threw it out there - do want to go potty on the potty? To my surprise, he nodded so I followed him into the bathroom and put him on the toilet. He sat there for about a minute or so and then wanted to get down. I think this was more pretend pottying than truly a conscious effort on his part to go, but I found this encouraging. Madeline really didn't have a true interest in the potty until she after she turned two. I had tried to no avail to start her at 18 months with her just as willing to potty in her trainers or panties as regular diapers. And then of course you hear that boys hold out to the bitter end to train. My friend's little boy is fully potty trained just as he nears his Kindergarten deadline. So the fact that Isaac even considers the potty something other than a bowl of water to play in is highly encouraging to me. I'll take it on his time and cross your fingers he trains up faster than Maddy did.