Spanish stamina

One of the things that amazes me the most about living here is the sheer stamina of the Spanish, or at least of the Catalans we dwell amongst. Granted, after last evenings festivities, I am not exactly feeling spry and lively, but these people are amazing. It is Wednesday night, at 10:25 and there is a party building up downstairs. We can hear their doorbell ring, so we know people are just arriving. There are thee guys who live down there, all in their mid-twenties, and a couple of girlfriends are kicking around. They all get up and go in the morning. They will probably all go out in about half an hour, this is what usually happens. They do this several nights a week. We haven't figured out their schedual for when they get in, but it is at all hours. Someone frequently around 3 am and then someone gets in usually at around 6am.
We asked X's cousin about this, and this is normal. Most clubs don't open till 1am, and close at 6. The "after-hours" clubs start up at about 6:30. It brings the thought of raising teenagers to a scary level. As the cousins put it, the problem is not that they go out, its that they never return.
The school kids are the same. They don't go to bed until at least 10 pm on weekdays, and get up for school at the usual time. Weekends, they stay up till 12 or 1 am. These are grade school kids, you know 6 or 7. And the siesta? No such thing as far as I can see. Kids have a two hour lunch, first hour eating, then an hour playing outside in the street. Now I know what I would be like and what my kids would be like after that.......

The flip side of the coin on this is that it is a culture that truely enjoys their children and has no desire to pack them off to bed as soon as they can. Still.........how do they do it?