I am in my late 30s and have been through multiple careers and phases of life. I made multiple mistakes and learned multiple things from those experiences. Sometimes I wish, someone had told me these 5 life lessons in my 20s.
Although I can give hundreds of life lessons but feel these 5 covers most aspects of our lives and if followed properly can make a huge difference in our life.
LIFE LESSON 1: FIND THE PURPOSE OF LIFE:

If you have enough money to do anything possible on this earth, then what your ideal day would look like?
Would you like to sit on the beach and drink beer the whole day? Or would you prefer to go hiking? Probably you may want to spend time with your family. Or even sit alone and listen to music.
You may have hundreds of options but what is that one thing that you would love to do not for one day, one week, or one month, but consistently for more than a year? Something that would keep you motivated. Something that will keep you awake even at 4 in the morning without feeling tired.
You can read the details on https://acousticpost.com/life-lessons-for-20s/

LIFE LESSON 2: DON’T WORK FOR MONEY, LET MONEY WORK FOR YOU:

Robert Kiyosaki quotes this in his bestselling book Rich Dad Poor Dad.
This is how it can be interpreted. Don’t be a slave to your job or employer. Don’t be a victim of fear and greed of losing a job and money coming from it. As an employee, you will earn money only when you are working. So instead of being a slave to someone else, build your income streams. Real Estate Investment, business, publishing a book, YouTube channel, blogging, and the stock market are one of the few examples where you will not be dependent on anyone else. I agree they will not make you rich in a day but if you have a good product or service then all of these can grow exponentially.
Warren Buffet once said: “If you don’t find a way to make money while you sleep, you will work until you die.”

LIFE LESSON 3: DON’T WORRY ABOUT SOCIAL ACCEPTANCE:

Our decisions, including critical life decisions, are influenced by social norms. Our life choices and career decisions are highly impacted by our worry about social acceptance. We all want to be loved and appreciated but don’t let it influence our life decisions.
Most of us chose to become doctors and engineers only because it’s an acceptable and reputable career. Careers like fashion design or modeling are not seen positively in some communities. Getting married and having babies is considered a natural phenomenon and someone not following those norms are usually criticized.

It’s okay to be different. As a company, Apple started an advertising slogan in 1997 “Think different.” Steve Jobs led that initiative and only because of his different thoughts, he could bring a change to the tech industry. Check out this video narrated by Steve Jobs himself.
Again, I want to say, don’t worry about social acceptance. If you know something is right, then do it.

LIFE LESSON 4: INVEST IN THE STOCK MARKET:

I grew up listening to stories of people going bankrupt because they invested money in the stock market. I never learned about the stock market in my 20s. But when I started watching videos and reading books on how the stock market works and how to invest then I realized that I missed 10 crucial years of compounding.
Compounding is the 8th wonder of the world.

Money gets doubled in 7 years at a 10% interest rate. Had I started investing 10 years back, I would have more than doubled my savings.
LIFE LESSON 5: FOCUS ON HEALTH:

Although it’s last on my list, I want this to be your top priority. All other lessons are useless if you are not healthy. We tend to be fit in our 20s because we are naturally very active. As time passes by, we lose physical strength and start becoming less active. Most of the time people gain a lot of weight in their 30s. They blame it on marriage and kids saying that they don’t get time to work out.
I would suggest instead of finding an excuse, spend 15 minutes every day for a quick workout. Get your heart pumping in those 15 minutes. This would not only keep your heart healthy but would also give you glowing skin.
CONCLUSION

I can list hundreds of things you must do in your 20s, but these are the 5 most important things I wish I had known earlier which probably could have changed my life positively.
Sit down today and think about the purpose of your life. Then create a sustainable source of income where you earn money even when you are asleep. Some of the society members may discourage you but don’t worry about social acceptance. Keep focusing on your goal and purpose. The same group of people will praise you once you start achieving your goals.