I was cruising through the Western Express highway (in Mumbai) when I noticed the road broadening work going on alongside the road. Giant excavators were cutting through the cliffs on the sides and the rubble (actually large stones) was being removed by other gigantic off-highway trucks. I could't but appreciate the 'might of man'.
My thoughts moved to the wonders on the world - the pyramids of Egypt, The Great Wall of China and our own Taj Mahal. The gigantic structures made in ancient mediaeval times are a but a reflection of not only engineering skills but more so of hard labour. The city of Mumbai in fact is a wonder in itself - a group of 17 small islands being made into the most happening city of India. In fact 50% of South Mumbai ('town area' as people here call it) is built on reclamation land.

It is difficult to imagine such monuments and cities to be built in the present day world. How did the ancient civilizations do it? The answer probably lies in the working habits of the times.
In ancient mediaveal world where people were primarily agriculturalists, the practice was to work from morning to evening. People used to be asleep after sunset and used to get up early morning, sometime before sunrise. An emperor who would employ such labour would have to just provide for shelter, clothing and food - no other expenses were required.
In the pre-ancient days when man was a wanderer - humans were on the call day and night. Man had to protect himself from wild animals even when asleep. And life before agriculture was a full time search for food - morning to evening.
Contrast this with the modern times - with the rise of industrializationtion came the 9 to 5 routine and we started working just a part of the day and spend the rest enjoying ourselves. Initially there was 6-7 days a week but slowly it became 5 days a week in advanced nations - and the schedule is soon picking up elsewhere as well.
Slowly we are working lesser and lesser while our standard of living is growing better and better - even the labourer of today has to work less than what a labourer of the ancient times did!!
A sticker that I read in the local train that epitomises the concept -