i believe in reality if it happened in the future only few people keep their faith in bitcoin.
most people would leave and scared about bitcoin price dropped to $1.
i personally it depends on the situation , i could be leaving bitcoin forever but there is no harm to invest small amount as my faith to bitcoin.

yeah of course if bitcoin drop and headed to the price of $1 maybe everyone will experience panic selling. will not anyone think to survive and hold their bticoin. because a lot of people would think that bitcoin will no longer potential. but for that to happen would be very difficult

Nope. it will never happen. because BTC become a need of many people now a days. As u say what will i do if its happen then i will surely buy more Btc.

That's the right thing to do, as we know bitcoin can grow again in future, its just matter of time the only thing we need is a patience and faith in bitcoin.

I think after this major drop bitcoin will never return, people will start panic, solding bitcoins also will stop using it. But maybe my prediction is wrong.

There would have to be a catastrophic failure or some serious security flaw for that to happen.

Is it possible to bitcoin to drop to $1 again? what are the theories and how could it happen if this happen this could mean that people are dumping bitcoin for some serious problem if that is the case then it's time to invest on other altcoin..

You mean there is no point in talking about a dead currency when it drops to $1 or you find it already to be a dead currency? Either way, Bitcoin will only (temporarily) die when there is no power and/or no internet connection. Price doesn't matter in this case. Even if Bitcoin is worth only $0.10 then the technology itself is still running perfectly fine.

It depends on what is the reason why the price drops from $400 to $1 if that reason is not too serious  I am going to buy plenty of it and wait until the price rockets so I can earn much.

That doesn't makes it a dead coin when it's still worth of $1 and there is no death to BTC. Whenever the price goes down, people will start buying and it rises again.

And FYI, this forum is not dedicated to only bitcoin just because the name says so. There are other currencies too.