If you aren't in the moment, you are either looking forward to uncertainty, or back to pain and regret.
I like challenges and I don't believe in failure. I don't believe in regrets. I believe suffering, failure - all those concepts - are things that are absolutely necessary to make us the best people that we can be, the best at whatever we want to do.
Usually you regret the things you say no to.
I come from the philosophy of: "Whatever happens to me is the greatest thing that could happen, no matter what." Sometimes in the moment I have a regret, but then I have found myself every time down the line saying to myself: "I wouldn't be here if it weren't for that so called failure."