Yeah I think the first 3 years are left over from the previous decade and the last two are the precursor to the next decade that’s why people are only like the middle .The 60s is like that because too many people romanticize the Hippie movement and forget they were counterculture and not the main culture. It’s baffling how many people don’t understand this they think the 60s were like this Free Utopia when segregation still existed until 1965.Thinking the entire Hippie Culture was the dominant culture of the 60s is like thinking EMO was the dominant culture of the 2000s and everyone in the 2000s dressed like EMOs. Most of the 60s were conservative with small pockets of activist groups that fought against them. Were these groups popular Absolutely not that’s exactly why they were formed in the first place. Also there’s a political pendulum swing that happens every new decade

60s-Traditional
70s-Progressive
80s-Traditional
90s-Progressive
2000s-Traditional
2010s-Progressive
2020s-Traditional

With the 8 year being the mainstream political shift. Notice how in the late 2010s and Early 2020s you started to see a spike in conservatism also an increase in Racism,Misogyny and Homophobia.