I don't know that anyone outside of my family would necessarily get the reference. It's from a Peanuts comic from, oh, probably the 60s or 70s. According to Google, my family has also mangled the line, which should be "I was going to say I saw a duckie and a horsie, but I changed my mind."
Anyway, the kids are lying back watching clouds, and Linus of course pops out with seeing all sorts of miraculous things, and when Lucy turns to Charlie Brown and asks what he saw, that's how he answers.
Everyone bored yet?
