Taking the bad with the good

Why is it that we would go through something bad just for a little good. A good example is when people drink. They will go through the experience knowing that they could have a really bad hangover the next morning but you do it just because its a way of us justifying the good with the bad. This kind of idea goes with a lot of things in life. You want to go out to a good fancy dinner with good service then you can expect a larger bill. If you want to drive a really nice car then you can expect to have a to pay more to maintain it. If you want a better a better job then someone else then you can expect to have to go to school for longer or take harder classes then someone else might take. This is just like the glass is half empty conundrum. Its all how you look at it. Things can be seen a good or bad, half of full but no matter what angle you look there is always two sides to everything. Thats just part of taking the bad with the good.