Three decades of mistakes has taught you that happiness does not come with a price tag. No amount of gadgets, take-out food, and/or social media can ever replace the warmth and comfort of a good home-cooked meal with your loved ones. You also probably must have realized by now that savings and good insurance schemes should be a priority.
After turning the big 30, you must have learned that running behind success is like a wild goose chase; it is limitless, the more you get the more you wish to achieve. A job is no longer an option but a necessity. However, it no longer ends at paying bills or preparing for the future. In case you haven't noticed, company matters, and hanging-out with successful people makes you better at your game.
In the past 30 years or so you've realized to make the most of the present, and at the same time just being in the moment and doing nothing but bearing witness to life. Experiences have shown you that you alone are responsible for your actions and fate. Pain and suffering are two different things; pain nudges us to make a change, while suffering is self-inflicted.
Experiences, mistakes, and people have taught, nay, trained you to let go. Looking back upon the thirty years or so of your life, you can almost see a pattern which has led you to be the person you are. Hopefully, you've also learned to forgive - if not forget - others, but most importantly, yourself.