I honestly believe that every one of us has their own story to share regarding their regrets into selling their BTCs early. While it may be painful to recount and recall these memories, those are just the lessons that we live by in order to prevent history from happening ever again.
Like what some have mentioned in this thread, the best time to purchase BTC would be the time when you can afford it. Likewise, you can never be too late in purchasing BTC and making it as your long-term investment.
Most times as humans we feel more regret for the action we didn't take than the ones we took.
If the current Bitcoin price is the lowest and continues to surge to a high level, of course it is all the deepest regrets, but if the price of Bitcoin drops deeper deeper, of course the umpteenth time.
But at least we can still do activities in the crypto market by conducting trading or investment in the long run, if we believe in the price of bitcoin can penetrate $ 1 million.
For me in the crypto market there is no regret while you believe and the pahan with the way it works Bitcoin.
At the end of the day, we use the price history index of BTC as the basis of our plan for long-term HODLing. If it's price skyrocketed in the past, what stops it from doing the similar trend a few years from now?