I don't think there is a wrong time to buy Bitcoin, I concur that you should not be greedy but even if you buy Bitcoin when the price us going up and you are a long term holder you will make it.
There is no right or wrong time to invest in Bitcoin, a lot of people just have a different idea about investing because of the different seasons in the crypto market, they assume that they always have to wait for the bear season thereby timing the market. It is extremely difficult to time the market because it's impossible to always predict the market.
The greedy by I don't concur with are those looking for cheap ways to get Bitcoin, these greedy ones are susceptible to getting scammed if what they have.
I concur with ignoring fear in Bitcoin investing, fear can make any bad news sound true even if they are just propaganda against Bitcoin.
People that have gotten so used to investing in ponzi schemes are the ones that are always always quick to look for quick ways to make money from Bitcoin and also quick ways to buy Bitcoin, this is the reason why they always end up incurring losses.