I'm Left because my guiding principle for how countries should be managed is "The greatest good for the greatest number".

This puts me in a collision course often with "lefties" who are just tribalists mindlessly parroting slogans and cheering for celebrities of "their side", because they never validate what they hear from "their side" against any such principles, which is how you end up with "lefties" such as tankies or the kind of "feminist" who just happens to be a high middle class woman who thinks "breaking the glass ceiling in corporate management" is far more important than reducing the 40,000% wage difference between CEOs and the average employee, in other words putting "loyalty to the team" far above and beyond doing what's best for society as a whole or simply trying to further their personal greed objectives using the some "group identity" as cover.

Those not capable of putting personal upside maximization or petty emotional needs (including all those related to tribalism) to the side if that is required for the greater good, are not leftwing, IMHO.

Left is about how you feel regarding hierarchies.

Being against discriminating people based on gender or orientation is being against hierarchies that put women or LGBT at the bottom; being against exploitation or favoring unions is about improving the situation of people who are below in a currently existing hierarchy. If you want absolute gender and LGBT equality but wholeheartedly support the right of Boeing's shareholders to gain lots of money and not to get taxed too much, you have some leftist ideas and some right-wing ideas. If you want to establish absolute socialism but think gay people especifically shouldn't kiss in public, you have some leftist ideas and some right-wing ideas, because you're putting gay people at the bottom of hierarchy.

In the US, worker rights and social participation in the economy often gets left out of "what it is the left" because of the Cold War persecution against anticapitalist ideals and the predominance of the Democratic Party's old guard at establishing discourse, which creates a skewed vision.

I'm left by default because I don't support violent coups, and I don't particularly care what some people choose to do with their genitals. Pretty pathetic when I put it that way, but that's just how it is..