Graduate School Advice - Do You Go to Graduate School?

In the nineties i had a plan to get my ph d and exercise physiology. However, after doing the math, i would be 60 by the time mi graduate with a ph d. Which would leave me maybe ten to 15 years to work before retiring. One alternative is to start a small human performance testing lab as a side gig,. slowly building up a strong client base while maintaining his day job as an office manager for a major southern california university. I am not a big believer in get the degree to see what options it opens up. Now, at the age of 53, do you go get your ph d? Because you have this idea for some sort of performance testing lab