Big Boy's "Reading"

Why is it that when you want your kid to come up with something to do on his own for a few minutes while you put the dishes away, he wants to play in the dishwasher, but when you want him to go to sleep, he wants to sit quietly and read to himself for 30 minutes?
Big Boy is only 2.5 years old, so yesterday at naptime when he said he wanted to read himself, I figured he would just look at the pictures in the Curious George book before going to sleep. So I left him to it. But when I went back downstairs to put Little Boy to bed a half-hour later, I heard Big Boy in there, reciting perfectly the words from one of the Curious George stories.
Mind you, I'd tried to get him to watch TV for a few minutes while I wrote on the blog yesterday. To no avail -- he wanted to sit in my lap and push buttons on the computer. At dinner at a restaurant, I tried to get him to color for five minutes while we waited for our food. But he wanted to get in and out of his booster seat about eight hundred times.
Then, after dinner (this is not related, it's just what happened after our food finally arrived and Big Boy ate his pizza, with ketchup on it, upside down), I was trying to get him into the car but he wanted to lean up against the wall at the side of the parking lot. He said, "I'm busy. I'm poopin'." His new thing is that he can't sit down while he's pooping or after he's pooped.
So I waited. My dad (we'd gone to dinner with my parents) was laughing and saying this would be a good subject for the blog. I think he was joking, but whatever!
So then Big Boy is running along that wall in the parking lot, trying to get away from me (don't worry, there's a big landscaped swath between cars and wall, so he was running in that). He was alarmed and delighted when I jumped over a bush to catch him. I realized then that he hadn't pooped after all, so I loaded him up and off we went.
Before bed, he wanted to sit and listen to music. Of course. I'm trying to get him ready for bed and he wants to sit still and listen to music for 10 minutes. And then, we're downstairs in his room, trying to get him into bed, and he wants to sit and read again for 10 minutes. By himself. I just can't win! But I was very impressed that he got about 60 percent of the words exactly right -- despite MrDartt and my abbreviated versions of the very long stories!