You know what, I don't agree. The rule is actually simple; you buy Bitcoin and keep it safe. That's all there is to it. What's not easy with that?
The thing is that people are complicated. We want to trade. We want to analyze charts, develop patterns, make strategies on the best entry and exit points, and so on. We want to invest in altcoins for better opportunities. We get into ICOs, IDOs, DeFi, staking, and so forth. And we are emotional, too.
But what is there in the entire history of Bitcoin that says mere HODLing is not the best thing to do?
And that is because people want to feel that they are doing something to improve their situation, it is very common that after a tragedy happens there are calls for the government to do something and the government does, but many times they make things worse by their actions than if they did nothing, however if the government did nothing then people will complain about the inaction, people see inaction by nature as laziness when many times that inaction is the best thing you can do, and this is the case when you are holding your bitcoin, once you buy there is not much else to do except to keep it, but many people cannot simply accept this and decide to become traders only to lose their investment to other more talented traders.