I turned 68 yesterday. For me to stack 5 years in a row and not spend any btc and then expect to spend 50 years with wealth is not happening.
of course if you are 40 and stack until you are 46 it could happen for you. Yeah you may get 30 or 35 years of time after the stacking. But to be 46 and wealthy is not so bad.
Happy 68th young man. I think you're doing just fine. At least your mining gives you a chance to keep on stacking.
Any time is a good time to start stacking. I bought my first bitcoins shortly before my 65th birthday and rode out my first crash (from $266 down to about $50) a few weeks later. I didn't panic sell, I continued to stack. Within a few years I was using some of them to buy several millions of dollars. It's never too late.