It seems to me that self-interest is an essential aspect of socialism every bit as much as it is of capitalism.

I want a decent health service which provides good medical care when I need it and which doesn't charge me money to use it. I want public transport which is reliable and comfortable and inexpensive. I want to have the protection of a trades union and have a job where I have some control over my working environment and on what I do every day.

That is all about self interest, short-term as well as long-term, and it seems to me that I am more likely to get those needs satisfied in a socialist context than in one which is built round private profit.