What are 20 harsh life lessons everyone should learn in their 20s? originally appeared on Quora -- the knowledge sharing network where compelling questions are answered by people with unique insights.

Answer by Max Lukominskyi, life and productivity hacker, on Quora:

Life has already begun. There is no interlude. Nor is there a trial version. Your every decision matters. Your online friends are fake friends. Unfortunately, it's true. Most of them do not care about you and will not come in your hour of need. If you fall in love, be ready to get your heart broken. It is tough and it hurts. Your studying career does not end after prom. Knowledge is crucial. If you are not willing to be left behind, keep studying. Your family members are the most important people in your life. They are the only ones who care about you. Treat them well and appreciate them. Your weaknesses do not matter. Learn to accept this. The only things that matter are your strengths. Improve them. Everything worth doing takes years. Do not expect to reach your goals too quickly. It will probably take much longer than you imagine. All the opportunities for growth are beyond your comfort zone. Make leaving it a habit. Find your discomfort zone. Enter it. Broken relationships are not worth staying in. Do not waste your time on things you cannot fix anymore. Let them go and move ahead. The world is full of injustice. There are plenty of unjust things you are likely to face within your lifetime. Be ready! Luck comes to those who work hard. Good things do not come to those who wait. Persistence and hard work are the only prerequisites for luck. There is no perfect moment to start. If you want to start doing something, act now. Do not wait for a better moment. It will never come. You cannot be everywhere and have everything. Learn to make the right choices and commit to the things that matter most. Every person in your life should be appreciated. Do not take people for granted. Experience and emotions are your best investments. The traditional measures of success -- fancy cars and houses -- are no longer relevant. Emotions, memories, experience, knowledge. These are the things that matter. Later often means never. Do not postpone anything. Live now! Success equals perseverance. Do not give up. Stay dedicated to your dreams. Chasing them is difficult, but it's worth the struggle. Regular workouts are crucial. Take care of your health and body. Exercise regularly and make sure you are in a good shape. Your failures do not matter. Only wins count. Therefore, do not be afraid to fail. Nobody will help you. You have to help yourself.

Feel free to visit Perfect Impulse, where I share handpicked thoughts on self-improvement, productivity, and life