What you have mentioned OP can also apply to both new and investors as well.

As a general rule, a person should start investing by using a portion of his income designated for that purpose. Investing should always come from your savings. If you prioritize investment over than your personal needs and monthly obligations, then there is a higher chance of failing and that person prematurely cashing-out their investments at the wrong time.

While the price history index of BTC had increased over the years since its inception, people should always remain smart when it comes to purchasing BTC. Sure, there may be a guarantee ROI in the next FEW years. But again, we are talking about YEARS of not touching our BTCs and HODLing them for long-term.