Very good advice.
In fact, I think that everybody should understand that crypto market is the same as any other market, stock market, Forex etc.
It's very risky so please be careful before investing.
The best strategy, in my opinion, is to invest only money youcan afford to loose and to diversify your investment.
Investing all you have in bitcoin will not get you anything, it will result to bankrupt or loss of funds, if you're going to invest make it more profitable by spreading your funds to some potential currencies inside the sphere.