actully, 13 going on 30 was not like Big at all... the difference is that in Big he wishes to be big and wakes up big... but in 13 going on 30, she wishes to be big and yea she wakes up big but so did every one else. it basically threw her ahead in time and every one grew up also, she just doesn't remember it. she time travels. Big just grew up by himself over night. therefore, it is not the same