Working on "the water thing"

Last night, in our continuing efforts to get Jack potty-trained, Char sat him down just before bed to go potty. A few moments later he said, “Mom, I just did the water thing!” Recognizing this as the milestone that it is, we all congratulated him. Lily gave him a high-five. I picked him up and hugged him and we had this conversation:

Me: “Good job, Jack! That was awesome!”
Jack: “I’m a big boy now!”
Me: “Yes, that’s great! Pretty soon you’ll be wearing underwear all the time.”
Jack: “Yeah, and then I can do the water thing and I won’t need my pull-ups and we can put them in a garage sale!”
Me: “Uh… well, yep… I guess we can sell your pull-ups in a garage sale.”
Jack: “Yeah, ’cause I’m a big boy now.”

For the record, I have no idea why he thinks his pull-ups are going in a garage sale, but it’s perfectly fine with me.