Yes, I think it does go against some of the stronger pulls of human nature. After all, we aren't social insects, who are usually one big happy family. All life is selfish to a degree, and it's natural to compete over resources rather than share them. That is the way we're made.
But one of the main problems with communism is motivation. A person is generally better motivated to work hard and put in 110% to better themselves and their families under a more capitalist system. If everyone simply worked to benefit everyone else and only reap the same rewards as everyone else, there is little incentive but to do the bare minimum of work to get your due. And I do believe that those who work hard deserve for themselves and their families - not for it to have to go to everyone else. One of the reasons I'm utterly against UK Inheritance Tax. You don't work all your life so that the State can take a big bite out of your efforts - or at least, you shouldn't, because you pay your dues to the State in life as it is. The rest should rightly be going to your heirs, not everyone else (or lining politicians' pockets). Capitalism is very far from perfect but it drives a sense of perfection.
Faust - it's socialist health care you speak of. And the same can be said of most public services you get in any country including the U.S., funded by taxpayers. It's not 'communism' proper. It works quite well to have certain services freely available to all and funded by all so a semi-socialist system is ideal; it leaves room for capitalism and competition and a drive toward better, while at the same time ensuring everyone gets a modicum of basic care and civilisation without having their possessions wrested from them.
A society in which you are not allowed to own isn't one in which I'd wish to live. Not least because communism is hardly free from corruption.