I do feel envy every once in a while. I try not to, and it isn't that I'm not happy for the other person, but I still feel envious. There is an 84 yr old in the hiking group I belong to, and she is in better shape than me (I'm 68 yr). I envy her genetics, lifelong healthy habits, etc.
And since moving to a retirement community I've become aware of what a large percentage of the older generation has pension income in addition to Social Security. By the time I started working companies weren't offering a pension benefit anymore (maybe some do, but none I worked for offered them). So I envy those people that they have pensions.
I remember being very envious in my thirties (after I goofed off traveling and enjoying life through my twenties) of younger coworkers who went straight from college to full-time employment and marriage and children and owning a house. But now that I'm older I realize if I had it to do over, I'd find it depressing to be like them even though some of it would be nice I would have to miss out on other different experiences.