It always spins me out that modern day folk can't work out what henges were for: they are so obviously calendars. The people who built them were no grey bearded

It always spins me out that modern day folk can't work out what henges were for: they are so obviously calendars. The people who built them were no grey bearded druids on acid. They were early scientists who had worked out that understanding the difference between spring, summer, autumn and winter was of utmost importance and a calendar that might not last more than a couple of years was useless, (you might have clouds on the longest day) People still scratch their heads at what mysticism was going on, why they put so much effort in to them, made them of stone or other durable but hard to work materials, and in places with good visibility to the horizon, and then wonder why people didn't live in them. People come up with crazy hypothesis for their construction and use. The simple fact is that if you didn't have a good one, and we're trying to live off seasonally farmed crops, you and your family would probably die. What's more interesting to me is how people without stone henges managed to survive. Presumably knowledge of the North star and stick henges, but if a modern day archaeologist found one of them they would probably mistake it for a tool of witchcraft.