Why RAW?

I know this must be asked a lot, but I didn't find the answer.

Some on this site say that taking pictures in RAW is the only way to go. However, I don't understand why. I've taken pictures in JPEG and RAW and don't really see the difference. I can adjust both and I've made some good pics in both.

RAW pics are huge and unless there's some great advantage, I just don't see the need.

Please help this new photographer out.