I used to be jealous of people for two reasons: good looks, and money.
I soon realized that being dropdead gorgeous carries a whole bunch of burdens with it that I wouldn't want to have to deal with. And I also grew older and realized that alot of what I thought I needed looks to get, I could get with just a whole lot of self-love and confidence and kindness.
The money thing was alot tougher, but recently there have been times in my life I have been blessed to be able to do alot of things that one associates with "having money"...blowing a ton on clothes, travelling alot, etc. And I have learned first hand that it is so easy to think life will be different when you have more money, but that really you are on this endless spectrum where you could always have more. So not a whole lot really changes. And you still have days when you are tired or bummed out. You still have days where you and your DH fight. You still have days when you are bored/exhausted/whatever....I realized that having more money doesn't really change the things that are important.
So, my answer is that I work on it and I haven't felt jealous of anyone for quite some time. And of course, now that I have my beautiful DD, I could never wish to be anybody else, because then I wouldn't be her mother!
So even tho money is tighter these days, i'm no less happy!