I was a socially liberal libertarian around the time of the 2003 Iraq invasion. It took a lot of reading many left leaning perspectives to get me to understand the failings of liberalism and libertarianism. As a USAmerican, I was so full of propaganda education, it took way longer than it should, but I also didn't really have any actual leftists to talk to about this stuff in my life. Since my marxist epiphany, I've been able to breadcrumb some folks in one conversation through years of my own development just by talking about historical materialist analysis and other concepts.