How common is mid-career crisis and how to deal with it

Ok lets say that they're earning a good salary but their time is more focus on work even if you're at home you're still working for money and your life will be like a rotating wheel. Most of the problems there are you don't have time for yourself since you're dedicated to your job even your day offs turn to office hours. I had these kind of problems before until I tried MLM everything has changed. On my first 6 months of MLM it was so difficult but after several months I resigned at my work because I got high amount in my MLM compared with my salary, after a year I established my own business and it was successful. Now I have my own control of my time unlike when I was working the office holds a lot of my time, I have time for everything like swimming, hiking without any worries. My advice to all of you are be a business minded person so you can unveil the secrets of life. Most of our mindset are focus only in employment lets change it. The common scenario of this is like this "Baby you should study hard so you can find a job" which is wrong for me. The correct one for me is "Baby you should study so when the time comes you can establish your own business" That's the correct one for me.