“Do what makes you happy!” is the best and worst advice of all time. The best part of this advice is the first word, DO. You should be doing a lot more than what makes you happy.
You should DO things. Take action and make things happen. Keep doing things. Do things that make you healthy, do things you love, do things to make you wealthy, do things to keep you safe, do things to make other people happy. Do new things. Doing is a key that will unlock many doors in your life. Doing will build up skills for your resume.
The more you do the freer you are because you are not limited. The more you do the more you expand and grow. The closer you will be to reach your goals. You will set an example and be a leader. Other people can follow a doer. You will other people permission to follow their dreams.