Re: What will be running in your mind if Bitcoin reaches $1000 again
I would say what’s wrong with the investors ? 
Though I highly doubt this will ever happen. The billion dollar market can not just disrupt itself. There are institutional investors, individual millionaires, million dollar worth mining farm network all over the globe! Believe me its whole ecosystem which is running 24*7 and 365 days.
If one element goes down from above list then another will always stood by bitcoin to support it.
Even though it goes down to such low level, we have no option to buy more and wait for recovery.
In case that bitcoin will drop to such a low value once again, then probably these institutions and whales will be first one on selling their coins as massive issue could have caused it. Though I highly doubt this will ever happen. The billion dollar market can not just disrupt itself. There are institutional investors, individual millionaires, million dollar worth mining farm network all over the globe! Believe me its whole ecosystem which is running 24*7 and 365 days.
If one element goes down from above list then another will always stood by bitcoin to support it.
Even though it goes down to such low level, we have no option to buy more and wait for recovery.
You're correct that it's highly improbable that this will happen as various supports and walls are there to avoid it. So, a probability of these support selling their coin may have been caused of a major issue with Bitcoin's technology.
If that happens, then I'll probably shift into some other crypto that has a better technology. But that is only if that were to happen.
I agree that the chance of falling to such a low level is minimal since bitcoin is the flagship cryptocurrency. And a vast number of other coins depend on its course. For example, the same stablecoins. Therefore, it seems that the fall of bitcoin to $ 1,000 is almost impossible.Its bottom, in my opinion, is 10,000-15,000 dollars. Whales, commerce, and many holders of this currency will not let it fall further.