Once you've pushed your own boundaries and either found your limitations (i.e., athletics, the culinary arts) or found the diminishing returns of certain activities (i.e., partying, video games, masturbation) then you are left with what's both a) actually important to you, and b) what you're not terrible at. Now it's time to make your dent in the world.

Stage Three is the great consolidation of one's life. Out go the friends who are draining you and holding you back. Out go the activities and hobbies that are a mindless waste of time. Out go the old dreams that are clearly not coming true anytime soon.

Then you double down on what you're best at and what is best to you. You double down on the most important relationsh.i.p.s in your life. You double down on a single mission in life, whether that's to work on the world's energy crisis or to be a bitching digital artist or to become an expert in brains or have a bunch of snotty, drooling children. Whatever it is, Stage Three is when you get it done.

Stage Three is all about maximizing your own potential in this life. It's all about building your legacy. What will you leave behind when you're gone? What will people remember you by? Whether that's a breakthrough study or an amazing new product or an adoring family, Stage Three is about leaving the world a little bit different than the way you found it.

Stage Three ends when a combination of two things happen: 1) you feel as though there's not much else you are able to accomplish, and 2) you get old and tired and find that you would rather sip martinis and do crossword puzzles all day.

In "normal" individuals, Stage Three generally lasts from around 30-ish-years-old until one reaches retirement age.

People who get lodged in Stage Three often do so because they don't know how to let go of their ambition and constant desire for more. This inability to let go of the power and influence they crave counteracts the natural calming effects of time and they will often remain driven and hungry well into their 70s and 80s.