I think these 'calculations' also include a lot of hope/optimism. A lot of people joined the crypto scene in 2017. For them all started with a the market cap rushing from one high to another. Then 2018 came and with it a lot of resignation. Now they think it MUST go up again soon.
I joined in the fall of 2012, so I remember 2014 and so on. Absolutely the same thing is happening now. With one amendment - the time period of the recession will be shorter than the previous one.
Ir could be since back then, crypto was definitely less known and introduced than it is now.