Why do people fight?

I was just thinking: Why do people fight? -married couples, especially. It's crazy. You love each other, but you get upset over crazy things and end up hurting the other person time and time again. I'm newly married and I'm still learning *smiles*, but here's a funny story for you:

The other night I was SO tired after work. I crawled into bed at 9:00 or so and fell asleep. I was out cold, and then I hear it: Crinkle. Crinkle. Crinkle. :) It was Jeff's granola bar wrapper! He was eating a granola bar and woke me up. And here's the bad part: I was SO mad. The crinkle of a granola bar wrapper infuriated me! :) It's crazy. Here's my poor husband thinking: "I'll never crinkle a granola bar wrapper again in my life"! :) Go ahead and laugh! It's OK! *grin*

I still feel terrible. I know we are human and fighting in inevitable, but why do we get angry over the little things? Dishes in the sink and empty toliet paper rolls are hardly anything to get upset about. We are supposed to be acting as Jesus would. So smarten up, Erin! :) The next time my sweetie crinkles a granola bar wrapper, I'll remember this verse: "Remind the people... to be peaceable and considerate, and to show true humility toward all" -Titus 3:1-2- And this goes for the bigger things. We need to (I need to *smiles*) act our age, and stop being crazy. We need to love God and love each other. That is what we are called to do...