My eldest has always been very straight forward, quiet, like a some imaginative play, is more so in the real factual world, adores books and his friends.
My second is 2.5 has continual verbal diarrhea and is the king of random. He seems to live in his imagination alot of the time and is always making things up about having verucas, funny things he has seen, what people have said etc. I must say he is very entertaining but if he was older i'd be very concerned as I really really hate lying. I know at this age his imagination is running riot but also wonder what he will be like in 5 years time? I hope he will work out whats real and whats not at some point.
It's just so strange how two children from the same genetic gene pool can be so different.