Generally, people invest onto something on the premise that their money will grow with it mainly because they BELIEVE in the commodity itself. In this context and in relation to the subject matter on hand, Bitcoin investors are banking on a hope that their investments will make it really big that will even surpass their expectations.
As you may have noticed, and based on my observations, there is no one who ever thought that their money will grow THIS big in Bitcoins as it is today. Hence, the billion-dollar dream is not impossible after all.
Definitely! Bitcoin has open up so many opportunities to people that has a dream of getting rich one day. Those who are mining in the early days I believe has no expectations that the price as it is today can be reach because even the price of hundred dollars is called a bubble before and here we are now today with bitcoin that has a price of thousand dollars and still being called a bubble that may pop any time.
People are investing into something and expect a return of investment after an "x" period of time. Bitcoin surpass all traditional investments in terms of return that may just lapse for a month or few months. I think no one expect that bitcoin can reach that amount this year given the fact that there is so many FUD spread by the people who are not in favor of it. The billion dollar idea is achievable. Example of this is the Winklevoss twins who are already bitcoin billionaires holding 1% of the bitcoin's total supply.