Outlive your enemies is as simple as that. You will encounter many villainous people who may or may not have influence over your life at some point, the intention of the quoted saying is that you “win” over those dickheads by living as good a life as you can.
A simplified example: one Manager I had fired me, but now I am living on my terms and in a place that is amazing, and he is selling insurance.
Life is all about adapting to changes, and an overall goal is good, but shit comes at you quickly and you either learn to deal with it or have a heart attack at 30.