What Protagoras meant by "man is the measure of all things"?

According to wikipedia the ancient Greek philosopher Protagoras said "Man is the measure of all things: of things which are, that they are, and of things which are not, that they are not" (παν μέτρον άνθρωπος), and "what is or appears for a single individual is true or real for that individual".... show more According to wikipedia the ancient Greek philosopher Protagoras said "Man is the measure of all things: of things which are, that they are, and of things which are not, that they are not" (παν μέτρον άνθρωπος), and "what is or appears for a single individual is true or real for that individual". In other words, he was a proponent of some kind of idealistic relativitism.

I would like to ask him: "Do you think that all ideas, notions and opinions are of equal value?"
For instance, some (in fact, few...) people think that states can find welfare better with a communist system, others believe that a capitalist ("free market") system is better. But historical experience showed that the latter opinion is better.

Did Protagoras mean that if I think that commumism is better, then this is true for me, if I think that capitalism is better then that is also true for me?
This is folly!
Update: I am not a student doing homework. I just like to read philosophy and I had this inquiry long time ago.
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