If you’re not a socialist at 20, you have no heart. But if you’re not a capitalist at 40, you have no brain.
The end result of socialism/communism is that it pits all kinds of groups against each other as they fight for their share of the resources.
A classic example was in the Soviet Union with farmers vs industrial workers, as food was siphoned to the industrial centers, leading to mass famines in the countryside.
Or maybe the non-socialist at 20 had a better education than the socialist.