Where do they come up with these things?

So lately Colt has been saying some of the funniest things. He's with me most of the time and I don't think it's stuff I say so I wonder where does he get the things he says? For example he will tell me something and it doesn't really matter what it is but then he will add "my dad told me that" or if he is with someone else "my mom told me that" most of the time it makes no sense so it always makes me laugh. My most favorite right now is "I am just fine" he says it when I am least expecting it and even if I shouldn't laugh because it's totally inappropriate I can't help it. We will be sitting down to eat dinner and I will tell him to come and he will look at me and in his sweet little voice with his cute little innocent face he says " no, I am just fine" We were kneeling down for prayers last night and I told him to come and he says it again "no, I am just fine" I could not help but laugh. One of those things that catches you off guard. I've come to expect it when we eat or when I want him to do something he doesn't want to but the prayers was the first.
Tallin on the other had will use these super big words and I sometimes wonder if he even knows what the mean or if he just likes saying them. 98% of the time he does use them in correct sentences. We were playing a game, hide and go seek in the dark, and I scared him really good and he says "Mom you frightened me" frightened really? What 5 year old says that. Another one he was on the phone with his grandma Kim and he says he is going to be courageous like batman. So funny I love my kids, life would be pretty boring without them..