False. The only thing you need to be a leftist is empathy, a willingness to learn, and a willingness to teach what you've learned.

Leave your disdain at home. Disdain is what begets purity tests and misunderstandings. Everyone is born ignorant. Don't disdain the ignorant. But don't waste your time with those who refuse to learn.

As hard and frustrating as it can be for those in the west to escape the mental conditioning and brainwashing they all go through. It's still sad to see people do that. Only to be indoctrinated into Marxist Leninist mindsets. Failing to learn from their failures of the last century. Which are often similarly, as bad as the capitalists.