There was a time when I thought that everyone had this kind of pain, and that I was just being ridiculous for acknowledging it. After all, if they can put up with the agony of being on their feet for 6, 8, or 10 hours a day, what the hell was my problem? I feel less ridiculous now, knowing that most people don't feel like they have nails embedded in the middle of their feet (thank you, plantar fasciitis) and a knife stabbing into their ankles after standing or walking for more than 3 hours, like I do.
I'm having a hard time finding something to compare it to, but I think I have an idea. Imagine that you get a job pulling the rope in a bell tower. You're not given any extra rope, but the end of the rope is a few inches out of your reach. The only thing they have for you to stand on to reach it is a desk chair that rolls.
So you stand on the chair, and it swivels around, and it rolls a bit (because the floor's a bit uneven and slopes to one side). You almost get the end of the rope, and feel your fingertips brush the end as you lose your balance and fall to the floor. You very carefully and slowly find a way to balance the chair, shakily stand on it, and pull the rope. After a week on the job, you're covered in bruises, you've sprained at least two limbs, and you're miserable and frustrated because there's no way to make the situation better. You're stuck with the tools you have to work with.
At the end of the week, you go down to collect your paycheck, and you tell the man who hired you that this is the most godawful, miserable job you've ever had, and you hate it more than anything you've ever done. He looks at you, baffled, and tells you that he was your predecessor, and that he found the work to be easy, enjoyable, and that it gave him lots of free time. He then stands up to hand you the check, and you realize that he is over a foot taller than you are. You go outside, and you find that you are actually a foot shorter than most people in the whole world.
It is then that you realize that it's not that the job was bad, it's that you didn't have the abilities that most people in the world already have available to them. Before, you might have felt that, if you quit that horrible job, some poor sap would go through what you did, but you know better now. You now understand that most people can do the jobs that are beyond your abilities, and that you can find something that is a better match for you.