User blog comment:Kittyfire/Random Topic Blogging!/@comment-3006892-20110919002350/@comment-3394114-20110919114822

Paradoxes? I love those! The most common paradox is the "grandpa" one and you probably know it. If you don't, here it is: If you travel back in time and you kill your grandpa before he meets your grandma, then your father/mother isn't born, therefore, you don't exist. But if you don't exist, then nobody kills your grandpa, thus leading to the born of your parent, then yours. But then, you kill your grandpa. And the thing continues.