There’s a difference between saying that it can’t happen and that it’s not going to happen. Sounds like the second because if you accept that socialism could work (as you say your friend does) you must also logically accept, since socialism can only work if people want it to work, that it could be brought into being. Whether it ever will be is another question. The answer to which is basically that it’s not going to happen as long as most people think it’s not going to happen.But I don’t think getting socialism is just a matter of convincing enough people. At the present stage of human social development socialism is, as a matter of objective fact (not mere opinion or desire), the only framework within which the problems currently facing humanity in general and wage and salary workers in particular can be solved. Since humans learn by experience they will sooner or later realise this. All we can do, as a minority of socialists, is to help this happening sooner rather than later by pointing this out at every opportunity.