When I was in high school I took a year long class in building trades.
We built a house in a new subdivision, there was twelve of us plus the instructor.
We started with an open hole, dug the footings, helped with the pour (puddling), framed it, sided it, roofed it and did all the finish work. It was a 2300 sq ft two-story with a two car garage.
Next lot over was empty, when we started. The day we started laying down the first floor joists and rim-joists, the crew next door (5-6 guys) had an excavation, no concrete yet.
By the end of the first day after the forms came off they had two stories with walls standing. Similar model to ours. End of day two they had a framed roof with paper down. We were still standing-up the first floor walls.
It was such a sharp contrast to see the pros at work, compared to total novices.
Truly impressive.