Why do I keep getting blindsided by office politics?

You keep getting blindsided because there is a whole layer to your workplace you have not learned to see yet: who really has influence, how decisions actually get made, whose word carries weight. It is not that you are naive or bad at your job. You have just been reading the official version and missing the real one. Power in an organization rarely matches the org chart. The formal titles tell you one story; the actual flow of influence tells another. Until you can read that second story, things will keep happening to you that seem to come from nowhere. The good news is that this is learnable. It is a skill, not a personality trait, and you can start building it right now. Begin by watching, quietly and without judgment: in the next few meetings, notice who people look at before they speak, whose objections actually change things, who gets consulted before a decision is real. Do not act on it yet. Just learn to see it. Once you can read where the power actually moves, you stop getting blindsided, because you finally know what room you are really in.