Is it possible to heal enough from a trauma for it to be as if it never happened to you?

Honestly, I don't think so from my experiences. I was in a very bad car crash and for months and months after it pained me and made me fear driving. And to this day, years later, it still is vivid. But now it doesn't hurt me. I think we don't have our problems leave us, but we learn to be strong enough to live with them and learn from them.

In really rare circumstances and with immediate medical help it is possible to completely over come a trauma

It depends on the traumatic experience, how much it affected you and the amount of time, and of course the person, but I would say it is possible. However, it's not possible for everyone.

I've found that it's both unfair and impossible to ask yourself to be the exact same person today that you were yesterday or a month or a year ago, regardless of whether there's any trauma involved. As you heal, you'll ask questions and find answers about your values, beliefs, and priorities that you might not have encountered otherwise. I think you can be just as happy and fulfilled after healing as you would have been on a hypothetical timeline where the trauma never happened -- with the important difference that you know a whole lot more about yourself and how to heal.