Most people just abandoned Bitcoin when the price is very very low. They don't even think that the price can surge and hit $100.000 because they think that is impossible. But then when the price slowly increase and hit many new ATH, they will start pay attention to Bitcoin although they still not trying to buy and hold Bitcoin.
They don't think to use Bitcoin as their investment because they are still prefer with their current investment such as gold and others. Or they don't want to open their minds to see the other opportunity to become rich in the future.
That's why knowledge and consistency in investing in Bitcoin are important, because many people who enter Bitcoin invest by just following other people, they don't understand Bitcoin's volatility and its potential in the future - even many invest like gambling/trading. Because if they understand how to invest properly in Bitcoin, they will not be affected by the market, and will continue to regularly invest in Bitcoin at any price using their discretionary income or money they are ready to invest, and hold it even more than 1-2 cycles until they can get a decent profit from it.
Someone who's really interested in Bitcoin investment must not understand how Bitcoin investment is before they start their investment journey. IMO, the first step to invest on Bitcoin is to know the safest wallet to store your Bitcoin for the long-run and also know how much to use for your Bitcoin investment journey before all this you also need to have a long term perspective.
A Bitcoin newbie should use DCA method for investing on Bitcoin because gradually investing gradually learning about Bitcoin investment. Like a student, we don't know much but when we attend classes and reading books we can know what we don't. Just trying to say that a Bitcoin investor can not know about Bitcoin investment unless he's making practice while he invest.