I will never sell under 20k$, even if Bitcoin go to 100$ ...
The peoples who bought Bitcoin at 19k$, why you are selling them now ? You bought at 19k$ sell higher than that !
If you don't beleive at this technology do not buy anymore.
Thats the real optimism.
It wont make sense if you dont believe on what your buying, common mistakes why most people lose so much in crypto because of their negligence to do research. People who had more knowledge and patience are the one who could rip the benefits.
People changes their mind and changes their priority especially in investing, investors are flexible they never say never and that's one of the rule of investing, if you sell Bitcoin, that does not mean that you don't want it anymore, there are a lot of reasons why people are selling, they want to make profit so they can buy more when the price make a dip, or they need money for emergency but will return their investment, it's not that they lose faith.