Knowing about Bitcoin is good but waiting to know everything before starting is a waste of knowledge, an investor ought to put that little knowledge they've got about Bitcoin to practice and learn more from their experience, learning is something that remains constant and the more you practicalise on what you've learnt the more perfect you get, in the case of Bitcoin investment, when you start, the more buy and keep hodling the more you get to understand what it's all about.
You are actually right bro, we don't have to know it all to start, but we have to start first, and along the line you will knows it all, either through experience or through people's experience and teachings, so anyone that has the intention of accumulating a very good stash of Bitcoin just have to start once he figures out his discretionary income, along the line he can work on ways to acquire more knowledge just as you have said already.
Also, everyone can't be on the same level financially, that's what some people don't understand, cause someone started with a $100 doesn't mean you must start with same amount whereas your discretionary doesn't permit you to, starting.
You are right actually, as every fingers are not equal, so as our finance, and cutting your coat according to your size is the logical thing to do if you want to be successful in your Bitcoin investment.
Another problem is that most Bitcoin Investors invest some part or even all of their emergency funds thinking to replace it back once their paycheck comes, not knowing that it's a terrible decision making because if emergency situation struck that particular time, their Bitcoin investment is doomed, so investing what we can afford at the moment is the best possible way to go about your Bitcoin investment.