Rightly said, every investor (Both Bitcoin as well as other assets) needs both knowledge and patience. It's not enough to just buy Bitcoin and hope for the best, you need to understand the market and the technology behind it because if you're not fully equipped with the knowledge you need to make certain decisions, you'll be exposed to lots of dangers that is capable of negatively impacting your investment and you might end up making wrong decisions and putting your investment in jeopardy.
And you're also right that the key to success is often HODLing for the long term, rather than trying to time the market or make quick profits and it takes a great deal of patience to HODL. This is a lesson that many new Bitcoin investors learn the hard way.
Right now everyone is happy with Bitcoin price as its going up (52k$ as I am writing). But not everyday is Sunday, there can be times when Bitcoin goes bearish and it can last for months. What should be the strategy during that bearish season and what to do when Bitcoin goes bullish? These are all questions one has to address when investing in Bitcoin. One can answer these questions only if he has sound knowledge about Bitcoin.
Also one don't need to study books or go for extensive study to understand Bitcoin. There are very simple scenarios out there that tells how Bitcoin has behaved over a period of time. Based on these scenarios one can easily define his future strategy.
JayJuanGee 6 different Hypo's gives you idea of accumulating Bitcoin for 5 to 10 years.
https://bitcointalk.org/index.php?topic=5132720.msg63394117#msg63394117