Even though bitcoin investment is not like any other investments where you can lose your money easily, I agree with you that success is not guaranteed in bitcoin investment, but investors are certain they will not lose all their money in bitcoin investment if they don't sell their bitcoin out of panic or fear. Since bitcoin investment is not risk-free, the best way to invest in bitcoin without having problems in sorting your daily expenses and becoming successful with your bitcoin investment is when you invest in bitcoin with your discretionary income or when you use the money you will not need for 4-10 years or more to invest in bitcoin so that you will not depend on your bitcoin investment to survive.
I don't think we are suppose to be talking about Bitcoin investment been guarantee or not because to me it doesn't make any sense though it is good to be realistic but how will one be talking about what they are investing into in such way. Even if it is not guarantee like you guys said it shouldn't be something you guys will be emphasizing on like this because this information can mislead or change newbie mindset towards Bitcoin investment because if we say it is not guarantee then what is now the difference between Bitcoin investment and trading since they both are not guarantee so I will advise we don't use this language or word here because of the effect it will have on someone who is yet to know what Bitcoin is all about.
what you said is not really right because is good to have full knowledge or information about something for you to make better decisions because half information is very dangerous. It not wrong to say that bitcoin investment is not guarantee. In every investment there must be risk and great people will not fear to take the risk. But one good thing about bitcoin investment is that you can not compare it with other coins in terms of potential that is why bitcoin will ever remain the best option to invest.
I don't know what will be considered complete knowledge of Bitcoin because everyday new things are still being discovered and optimization done to improve the Bitcoin network. Even when we had that Ordinal spam that messed up the Bitcoin network, it took the intervention of Bitcoin devs and other key players and also the death of the Ordinal hype to arrest the situation. This means Bitcoin is still an evolving technology that you cannot know everything about it before you start participating in the benefits it holds.
As a newbie to Bitcoin, what you simply need is just the basic knowledge to get started. The basic knowledge include how to buy, send and receive, the right wallets to use to protect your Bitcoin and the mindset to hold for long. You don't have to become an expert to start buying and storing Bitcoin. I will advice you to have a change of mindset because if you want to know too much, you will end up becoming confused because the more you know, the more it look as if you don't know much because there is always something new to learn everyday.