As this is the most common what I observe lately, there are a lot of reasons why newbies are behaving like this. The main reason for me is also social media or what they can see over the internet. For example on social media, their lot of popularity spreads hopium for people, especially newbies, and here the unrealistic expectation begins or it will just add up.
I see this is not an unrealistic expectation, but rather the greed they are targeting. After all, we must set a target which we will achieve some form of success. But the problem is that this is not accompanied by the targets they can achieve. This means that greed intervenes when they set targets to be achieved, which makes them look unrealistic. I don't care how many targets they set, as long as it's in line with their abilities and knowledge.
There are too many "influencers" that try to do this and that's the problem. If you keep on investing believing what those influencers told you then you are going to end up making a big loss, you should always be investing when you think that it would make you the most money, and only be able to do that if we are doing alright, not anything else.
I personally do not believe in any stories that influencers talk about, even if they talk about how much they won, because that's usually a lie, believe in what they can prove with data and papers, that way you would be able to see the reality they live in, and it's not as glorious as they claim it to be.