No, you were alive once before this life, and after you die you will live for eternity in either heaven or hell, the place you end up is determined por your faith in God. But saying that you only live once implies that you are an atheist, so you most likely will never understand and of this.
Judging from that username and that "question", you are from 2011. Use your time machine and travel back to your rightful time period, otherwise this time period's peace will be disrupted.