(I once heard this mashul from a friend of mine who has diabetes.)
Imagine if Hashem had created people differently than they actually are. Imagine if the skin would repel dirt, dust, grime, sweat and smells. Imagine if people's hair would stay clean and fresh-smelling always. In short, imagine a world where showers would not be necessary. People would not hear of the concept of a shower. Bathrooms would be what we now know as "half baths." It may sound far-fetched, but please try to imagine such a world.
Now, imagine if there were some people who were born with skin and hair like we all have. They would need to wash their body, their hair. Imagine how tough it would be for those people. They would have to have special devices (called showers) installed in their homes. They would have to watch out for dirt and things, lest they get dirty and people would realize that they have this 'condition'. And each night, while their sisters and brothers were being put to sleep, they would have to first be washed. Imagine the ramifications it might have on shidduchim!
You'd probably feel pretty sorry for this person, huh? So why don't we feel sorry for ourselves? We all need showers! Simple. We don't feel sorry for ourselves, because this is the way the world goes. Everyone needs to take showers.
Now, lets go back to the world of needing showers, and imagine a different scenario. Imagine if Hashem had created human bodies in a way that they would be unable to process carbohydrates properly. Instead of eating carbohydrates and forgetting about it, you'd have to check your blood sugar level, count the amount of carbohydrates you are eating, and give yourself an injection of insulin to help your body digest the food.
Would we all feel bad for each other? Would we all think we led this miserable existence because we had these steps to execute before we could eat? Surely not! Why? Simple. Everyone would need to do it, and it wouldn't occur to us that there could be an easier way.
Yet, often times, people look at those who have diabetes with pity. "Nebach, look what she has to go through." Or worse, people with diabetes pity themselves. "Why should I have to do all this?" Why? If the rest of the world were checking, counting and injecting, how would it make my life easier?
It's the sad and awful truth, when you realize that all of our dreams, hopes, and feelings are built around the immensely fragile and volatile world of our expectations. Looking around at all our friends, neighbors and relatives, we come to the amazingly false conclusion that there is a better way. That we don't have enough. That we could be having it easier. That we should be having more fun. And yet, what are those expectations built upon? An entire chain of people looking back over their shoulders at each other.
And so this becomes normal, because others do it, while that remains out of bounds because nobody else does it. And we all want these things, because the rest of the world has it. Yet, we would never contemplate buying that because nobody has it.
But imagine how much happier everyone would be if they could stop looking over their shoulders, stop trying to keep up with the rest of the world. I might be lacking something that you have, but surely you lack something of mine. And most importantly, I have this for a reason, and you have that for a reason.
Other people's situations and happiness should not, no, will not affect my happiness.