Interesting. I wonder sometimes what stepping out of my current life and into a life of FIRE will be like, though knowing myself, I don't anticipate being disappointed. I've been taking steps the last couple years to transition to an entirely new line of "work" (I put work in quotes because what I'm hoping to do is to make a part-time vocation out of a couple of my hobbies). Leaving a mark on this world is achievable in many, many different ways -- as a friend has pointed out to me in the past. If you mentor even one person in your lifetime, and that person pays it forward, then by any measure, you've made a difference and left a mark. In my recreational hobbies, I've mentored a few younger guys, and they regularly tell me how much that's meant to them -- and that's pretty damn satisfying. So I would say to the OP, with a little introspection I'm confident you will see you are already making a difference and will have ample opportunity to do so in the future (for example -- because climbing mountains happens to be one of the hobbies/passions that I am hoping to make a second career out of -- have you taken a newbie climbing with you, or introduced someone else to the ovewhelming joys of backcountry travel? I find that turning on that light for someone else, in the way it was turned on for me, is immensely gratifying).