COVID-19. People simply refused to do the absolute minimum to stop the spread of the virus. At least in my community, everyone was still socializing with friends and family (without a mask, of course), going out to eat, taking part in recreational activities with other people. Something as simple as "stay away from other people until we get this under control" was too hard for the American public. It certain changed my view of the people around me.
Actions > Talk. They were telling you their true views. People rarely say the quiet part(their views) out loud so it is valuable to be able to translate their actions into their true views.
When you know how others truly feel, it allows you to decide who is worth listening to. Not to say you shouldn't listen to people with different views, but instead decide whether they are telling you their beliefs or telling you what they think you want to hear(BSing you) and use that rate how trustworthy they are on the topic.