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