Hi,
The cause of the craziness is... Well, actually I see 3 main explanations:
1- Mass media communicate more and more about it. A few years ago, bitcoin was a geeky dark tool, only used for illegal purpose. Today it is presented as still potentially dangerous but also as a potential source of income. Journalists love sensational news. So they don't talk about those buying few and getting a bit more. They talk about the sandwich bought for several bitcoin, which would be worth thousands today.
2- People have had time to try, to implement, to see... They know that bitcoin is not merely about trading. They stick to this community because they want to be part of the "next revolution". The youth generation dreams about being the future Zuckerberg. Or Musk.
3- Governments and banks are realizing cryptos may become a real alternative. And they try to prevent this. But in order to do so, they must communicate about it!
I guess these three explanations must be taken into account. The good news is that more and more people know about all that. The bad news is that many of them only come attracted by lies and deceptive promises.