Life is composed of years. Years contains months, which contains weeks and days. Each day consists of moments. The moments that happened will never come back. Gone forever.
Each present moment presents you an opportunity to embrace freedom how your life is going to be. You can choose to be angry at the world. You can let the past events define who you are and who you are going be. You can choose to have other people dictate how you feel.
Conversely, you can also choose to be calm and collected. You can choose to be free. Free of how others think of you or treat you. You can choose to be happy.