In those years, nobody was buying Bitcoin because they could find blocks by mining for a few hours. At the time, Bitcoin had little monetary value and it was impossible to predict that it would reach the price it is today. Even the most ardent Bitcoin advocates and true believers sold their coins during price spikes. Aside from those who forgot their wallets, there are very, very few people who are constantly in the Bitcoin ecosystem who can wait until these prices without selling.
I made my first Bitcoin purchase in 2013, and yes, even though I believe in the future of Bitcoin, I haven't been able to hold on to it until now. This shouldn't be something to regret. Instead of living in the past, we should look to the future.
There is still a 4-year delay in buying Bitcoin, but why don't you keep your BTC and get rich because you sold it at the time. And now that you are hold with it, you will be a rich man with a happy life. If nothing else, we must not follow it anymore. Bitcoin makes you rich and rich, makes our lives happy.