There are always, and I mean ALWAYS, warnings about the trend before it starts manifesting.
Looking at this recent Bitcoin crash, was no different. There were like 5 warnings before it nuked to the goblin town.
But we, being silly emotional creatures are always busy thinking what we want it to do and get delusional and miss the clear evidences, which later on comes to bite us bad. We are left in emotional and financial turmoil. Thinking of quitting where we should've been buying had we paid attention.
It it quite natural. I am not blaming anyone. Even to this day, I fall for these fallacies. Key is to evaluate it, look back, see what you could have done differently. Facing your fears and mess ups' is the first step in a hero's journey.
One must not quit because of this. Its just too silly a reason for that. If you think you can make it here, you will.
Don't quit. Learn. Get better. Don't worship Twitter Gurus, VCs, Hype, etc. you get the drill.