Destiny
Do you believe there is some kind of destiny in the world? If not, how could we explain everything around us? Are all things reasonable? Maybe we can explain everything in different ways. Whatever the way is, at least, we can be sure about ourselves. That is the ultimately important thing we can control!
With the growing of us and the changing social environment, nothing equals our effort in our minds. The best reason for that is our desire growing with times. Once you attain your current goal, you will definitely have another and another one for the next. Desire is the root of pain. Maybe we are still uncouncious about what we are doing for now. Just go to check yourself and ask what would you if you only have 100 days left for the whole life. Have a clear image about the future you. After all, the life span is rather limited. Just try to do whatever you want for your whole life. Don't hesitate to say no for your desire, for which comes from your deep heart.
I don't want to erase anything that happened in the past. Without these experience, I am not the one standing here. If given a chance to live again from sometime, I still would make the same choice like before. Nothing can change the same me, I insist!