Learn to focus only on the present. The past is unchangeable so it is futile to reflect on it unless you are making sure you do not repeat past mistakes. The future is but a result of your actions today. So learn from the past to do better in the present so that you can succeed in the future.How great is this? All we have is right now. Literally. The past does NOT exist and we don't have access to it - we can't change it, so why dwell? Of course, we reflect and reminisce. But to live in the past and to base your mood on what has already occurred is exhausting and counterproductive. The best (and sometimes the hardest) thing we can do for ourselves is to live in this moment. There is no telling what the future will hold, and if we spend the present stressing about the future, then we aren't really living the life that we have right now. We are essentially just wasting precious time. All of the familiar quotes like "Carpe Diem" and "live every moment like it's your last" may seem so cliche, but they couldn't be more true. Being present and celebrating what we are experience in this very moment can only add to our excitement and satisfaction with life. Negative feelings like regret and resentment can only be experienced when living in the past. Stress and anxiety are often are a result of focusing too much on the future. If we can all practice being more actionable and embracing the present, we would all be infinitely more happy and balanced.
Oh... and just in case I wasn't clear...focus on the present, not the presents. ;)