I am in my 30s (not going to give an exact age here) and hopefully 1 year away from retirement if I don't fuck things up with my investments. And I am nothing special. I don't have an especially high IQ. I never had a super high paying job and do not possess any special skills or qualifications.
I just was fortunate to live with my parents for a long time (still doing this) to save money (I realize not everybody is this fortunate) work multiple jobs and save and invest. It also helps that I started investing very young (for example in my last year of high school I was reading books about investing such as Security Analysis and the Intelligent Investor and saving came naturally to me as early retirement was always my goal. Even as a teenager I knew I wanted to get rich to not have to work any more.
To answer your question yes I am still childless and single but once I hit early retirement I can get to work on fixing the single part by visiting (and staying in) the right countries.