How much time should there be in between a horrible friendship ending to be able to become friends again?

Like if you were friends with someone all throughout high school, and then suddenly right after high school you had a falling out.

Is it an acceptable time four years later to want to be friends with them again?

I really don't know.

You got over the whole situation, it just took you a long time. Is it worth it to try to start something back with them or do you just need to start a whole new friendship with somebody else? Not trying to replace them necessarily, but finding someone else that isn't them.

Everyone has different friends that make-up who that person is.

One friend makes logical decisions.

One doesn't think at all and just goes with the flow.

One is nostalgic and you just reminisce about the good times.

You are a combination of all of them and that's what makes it work.

Can friendships be mended after the amount of time that has passed between Y'all being friends surpasses the time that Y'all were actually friends?

What is the right thing to do in that scenario?

Will you ever find out the answer?