if im the owner of that 100bitcoin
i should'nt waiting to 20year
let's trade it and growing it with my trade skill
I Think at 10year i will be millionare (insya Allah)

2020 is just 5 years from now. It is possible the bitcoin will grow 40% a year, that is 5.37 in 5 years, if we times 400*5.37, that is $2,100 by 2020. With 100 bitcoin, you will have about $0.21 million.
The mass adoption is just getting started, so 40% per year on average could end up being just peanuts. By year 2020, i expect nothing less than at least 5k per coin.
In the end, it's just a fraction of users that we have; if the user base continues to increase the same way, there's no telling how far up the price may go.