When your son decided to stop playing?
I'm not really sure how to answer except to say it was his time. He loved baseball, and what it had done for him but it was time to pursue other passions, a professional career, and grad school. He had a year of eligibility left (injured junior year), but decided before his senior year started that he wanted to pursue an engineering job opportunity with GE after graduation. It was not a hard decision for him, and my wife and I agreed it was the right decision.
There were no second thoughts or "what ifs" that I'm aware of. My son maximized his abilities in his 4 year college career. He was fully aware of his abilities and didn't see anything beyond college baseball. Our neighbor was a couple years ahead of my son, and shared his professional baseball experiences in MLB and Korean professional baseball. I think our neighbors experiences solidified my son's decision.
I think my wife and I took his decision very much in stride. Our oldest son was doing well, and we focused our time on our other two sons. Baseball is always a topic of discussion in our family. I feel very fortunate to have picked up golf late in life and spend time with my sons on the golf course when we can. My oldest son was visiting over the Holidays, and we (all 3 sons + me) got out on the links to play some winter golf. Of course baseball came up. Baseball seems to be one of "the glues" between us, as I started them on the baseball path when all of them were in diapers. Now, they are teaching me to play golf. It is a true "circle of life"!
Best of luck @Francis7. Both of you will figure it out.