This brings me back when 2018, I also sold all of my alts turn it to BTC. Got 0.8 BTC from that and I thought I could hodl it for a very long time. When the BTC price hit as low as $4,000, I chicken out and sold that 0.8 BTC for just a little over $3,000. Regret that poor decision ever since.
The only way to be rich in crypto that you should not be active in the scene, just buy some BTC and store it somewhere. Only sell it when the price is good after many years just like your friend got lucky because he forgot about that 1 BTC he invested years ago.