If you do something all over again, you start again from the beginning.

It's already taken me two hours - I don't want to have to do it all over again. 这已经花了我两个钟头了，我可不想从头再做一次。

After the accident, she had to learn to walk all over again.

My legal qualifications weren't valid here, so I basically had to start all over again.

Why do we keep making the same mistakes all over again?

At the end of the season the vines are pruned, and the next year you start all over again.

See also: again (ONE MORE TIME)