Looking at the passed record of the movement in the price of bitcoin, you will notice that every time there is highly push in the price of bitcoin it drop to a certain level which it will maintain to gain more momentum, like when the price first hit $1000k it dropped but it could not go bellow $700, when it hit $9k it dropped but could not go bellow $5k now it hit $19k and is been dropping but have never go bellow $10k. So there is hope that the price is gaining momentum to go above $20k in the nearest time.
You talk about only recent 2 years. Before that you had completly different pattern. Price hit 1000$ and then it was dropping and dropping without any hope of recovery for almost 2 years. There was even Bloomberg article that BTC is the worst investment of 2014. Currently there are also plenty of potential news which can suddenly stop BTC and whole Cryptocurrenty market increase.
Imagine how hard it could have been for the people that bought at the top of the bubble in 2013, they needed to hold for several years, I'm sure that many people did not do that, sold, and they lost hope in bitcoin, those that held are getting their just reward and those that did not are getting punished by losing the faith in a great invention like bitcoin.
A lot of them did not have such a problem (e.g. me) because Mt.Gox stole their founds. There was no question HODL or not, cause you had 0 BTC anyway.