Impossible to understand

I can't understand my landlords. It's not the language barrier that confounds me. It's their habits. I'm beginning to wonder if they're afraid of the dark. I also can't understand how as engineers they don't understand thermodynamics. I shall elaborate. Also, I should clarify that my landlords aren't that old - they're maybe in their late 20s early 30s, so senility isn't an issue.

First of all, they're incapable of turning the lights off when they leave a room. There's a light at the top of our staircase that is FOREVER on. It's on whether they're home or not. Even if it's bright daylight out, they have to turn it on in order to ascend or descend the stairs. I'll wake up at 7am and the light is burning brightly just to irritate me. One time they also left a mini lamp on downstairs overnight. The thing was so bloody hot when I turned it off the next morning I nearly burnt myself. (They had also left their laptop running overnight... I haven't got a clue as to what prompted that.)

I also have a beef with their refusal to be responsible with the house heating. I believe I've gripped about how they crank the heat up to 27 degrees at all times and while I keep turning it down whenever I see it up there. Now that the warm weather has arrived, I've discovered a new issue. They leave the windows open while the heat is turned on... And I'm not just talking about opening up a window here and there to quickly air out the house, I'm talking "leave them open all day while the heat is set to 25 degrees."

I'll admit that I was the first person to start opening windows when the weather turned nice. But I at least turned off the heat before doing so. And when I was done downstairs, or when the day began to cool down, I closed the windows on my way back up. The next day when I came home from school, the windows were wide open, and as I mentioned above, the heat was turned up to 25 degrees. I was flabbergasted. These people are freaking PHD engineers! They should be smart enough to know that having the heat on while the windows are open is not going to do anything except contribute to global warming! GAH!

And then this evening. Oh my gosh this evening. I'm in the kitchen drying my dishes. The heat's turned on again, but whatever. Shunde (the guy) is upstairs in their room. Shuang comes home and yells his name. She leaves the door wide open while waiting for him to come down. It takes about 3 minutes for him to come downstairs. Meanwhile the door continues to stand open, sucking out all the warm air of the house. You know what she called him for? To bring in the groceries. She had brought them all the way to the top step, but was incapable of bringing them those final five steps into the house. I was beyond flabbergasted at this point. I was speechless and trying not to laugh hysterically. And the sad thing is, it only took Shunde 2 trips (hell, can that even be called a trip when the groceries are literally just outside the door?!) to bring in the groceries. She could have done it faster than him for Christ's sake!

Nothing I learned from my time in Asia can explain this behaviour. Can someone, anyone, please please please help me understand what's going on here?!