A question that really interests me about Stonehenge, Gobleki Teppeh and other such mysterious monumental sites is "
how many people did this?"
When we (now, and in the past) look at ancient construction projects, we instinctively tend to imagine fairly "brute force" construction methods. Basically, the way things are done now but with people powered trucks, cranes and such. Think of all those depictions of many people dragging huge loads on rollers or sleds. Very large groups of people using muscle power.
Thousands of labourers, hundreds of years. Herodotus suggests that it took 100,000 builders over 20 years to build a pyramid, 2m man years. In egypt, it's plausible. They had huge numbers of people, an empire, large scale slavery...
With stonehenge in 5,000 ypb britain, there are thought to be far fewer people. It wasn't a massive urban culture like egypt. People are thought to have lived in small dispersed groups at that time, with little evidence of large "political" authority that could command a large labour force.
Gogleki Tepeh's builders achieved similar feats 12,000 YBB. This is before large scale societies are thought to have existed at all, anywhere.
So either, (1) "civilised" society was much more common historically and ancient in origin (2) There were "pre-civilised" ways of organising very large numbers of people. Or (3), they had very clever building techniques that did not require many people.
Any of these answers, or some combination of them could add a lot of flavour to our understanding of the neolithic, culturally.