I am pretty sure shitton of people will be unloading their stashes like there is no tomorrow when btc starts to go above $50k. Not many will be left to hodl a full piece when it hits $100k.
When BTC goes above $100k and hits $1m, those who sold from $50k will be very sorry unless they owned and dumped at least 20 btc.
Yes, people tend to sell as if there is no tomorrow. We saw that when we reached the modest price 13800. People started selling so heavily that the profit turned into a loss for many. Only a day after the 13800, they kept selling down to 9700! We've seen many such crashes in 2017 and they all ended with 25%+ recovery. The next day it happened! We were back above 11K. I can only imagine how stupid those weak hands felt!
In the same way, we may have such crashes at any price level if the increase is too steep for a short time. We may fall from 50K to 30K for a day, and on the next day to be at 40K, and in 2 weeks above 50K. It could take longer, of course. It could take even a year, like in 2018. This won't be pleasant at all, of course. But if that is the price for becoming a millionaire, so be it!
I still remember 10 years ago, when I went into the bank and made a 5 year deposit with 4.5% year interest. I lived happily through those 5 years taking my profit. Until I heard of Bitcoin. What will be the interest of my Bitcoin deposit in 5 years? Incredibly high, for sure. Therefore, the price of suffering one more bear year is insignificant compared to the prize after that.
And finally, if someone truly loves Bitcoin, he won't be happy to sell all of them and to stop watching the price. It just doesn't work. He will learn one way or another. After 5 years, when he spent all of his fiat money, and hears on the news that Bitcoin reached a record heights 10x, 100x or more than the exit price, that feeling will kill all the joy he had when he sold them. Especially, if he has kids, who now have no money for a college or a medical treatment. My point is that we have to think in perspective - not for the next day, month, or year, but for a generation ahead. We have to be very careful what we sell and what we leave for the years to come. I've been thinking about it for 2 years and still don't have a clear and sound plan. I have to wait at least a year and see what will be the price after the next halving. Then I can make a better plan. And hopefully, my emotions won't interfere to sell most of it way too early! The other hard thing is to live with a profit that changes both ways by tens (hundreds, etc.) of thousands each day. That is no easy too! But this is our occupational hazard!