I have read several posts on this forum where people have claimed to have invested all the money they have on Bitcoin, I also read a post where a guy claimed to have used all the $20,000 his uncle gave him to also invest in Bitcoin, some even sold their landed property. The reason for these risks and others is the firm believe that Bitcoin would be $50,000 - $100,000 by the year 2019 or thereabout.

First, I must say that I admire the courage and high risk appetite of such persons. But, I must also warn.
Yes, It is good for everyone to have high hopes for Bitcoin, and also hope it gets to 100k USD in future, but you should also consider a safety factor in anything you do including investing.

Mathematically,

DO NOT Assume,
P(Success of future term) = 1 ; and
P(Failure of future term) = 0

This implies that, you must always leave a little fraction for probability of failure which in this case is the safety factor, no matter how little the fraction may be. Simply put, you don't have absolute control of what happens to Bitcoin and Cryptocurrencies in the future.

Invest wisely, only invest what you can afford to loose

Just a piece of advice.

What are your own suggestions?