I hear it all the time.
The mistake is acting like you only get to live for today. I understand the appeal of being present and living here, now. However, the idea of being present is misunderstood with actions that destroy the possibility of the future.
Indulging in any activity for a moment because you only live once is an escape. It’s an excuse to fulfill actions that are very short lived.
The perspective is changed when “you only live once” is within the realm of fulfilling a legacy. A legend is not just a pool of people that are near you, but the ocean of life that extends beyond the present and far into future generations that have yet to come.
The choice then is to decide whether you want to occupy a moment and a life that is short lived or a story that will last for ages. It’s your story and your life. Make it the one you always wanted to live; you only live once.