The price can only go to 0 euro of people lost faith in bitcoin. Which can happen if some new cutting edge technology comes and/or it will be banned to use bitcoin.
Youre talking about I dont know how many people exactly, but thats a ton of people to lose faith overnight.
And to see this even happen, it would have to be some historic moment back like in 2012.
Do not worry that day will never come when bitcoin can get to zero level, price is rising and it will rise in future too and we will be seeing all time high in coming years.