Just like you, I missed the dip in 2019. I don't deeply regret starting my Bitcoin investment late, but I do regret what the amount I would have invested in Bitcoin then has turned into in 2021. but due to my lack of knowledge about Bitcoin then, I started hearing about it in 2018 and 2019. But at the time, I didn't even know anything about blockchain technology; I didn't know where I could buy or sell  bitcoin because I wasn't aware of CEX, DEX, or anything like P2P. The worst thing that could happen to someone is when they are not informed or when they lack proper knowledge about something very useful. The worst of it then was that I never knew that I could buy BTC with $500–$680. All I thought was that for me to buy Bitcoin, I needed enough money that could cost 1 bitcoin. I was not aware that I could have just used the $600+ I had then to buy Bitcoin. In 2021, with BTC's new ATH, I had regrets about the 0.165 bitcoin I would have bought in January 2019 with just $600+, because the price of 1BTC was still $3,800+ then. I am not claiming to be a professional now, but with the little knowledge I have gained, I try to buy when I see an opportunity to, gladly using dollar cost averaging to accumulate gradually, no matter how small.