in our world today, lots of people have accepted bitcoin and has been using it.
But the majority, still won't accept the concept of bitcoin and its usefulness and still prefer fiat money.
As how closed those other people's minds are right now, how much time do you think it would take for everyone to accept the concept of bitcoins??
Or is it just a childish dream and will never happen??
I'd rather say it is a fantasy (or even a lunacy of sorts)
Basically, the point you raise has nothing to do with accepting or rejecting the concept of bitcoin (usefulness, or utility, is an entirely different aspect or point, just in case). Many people don't have a clue about the concept behind fiat money they are using daily but do they care or does it somehow limit their ability to use money? To drive a car you don't need to be a mechanic to know which parts the internal combustion engine consists of, you don't have to be an engineer either to understand how it works. It is the same with Bitcoin, ultimately it all comes down to convenience and utility