With Bitcoin and if I ever needed to sell Bitcoin but I couldn't do it in my own country then I'd just try to find a buyer from outside of my country to
Sell them my Bitcoins for dollar and receive it via paypal or credit card, problem solved.
No such things as stupid questions, and imho this question is far from stupid.
While a ban in practice wouldn't really be feasible, governments can make it very hard for bitcoin if they want.
To the point where legally exchanging to fiat wouldn't be possible, or that vendors can't officially accept btc no more etc.
Everyone is saying we will all keep using it, and of course most of us will, but this would be a serious downfall for bitcoin if it ever would happen.