So you never make any judgments at all about what other drivers are likely to do while driving yourself?
I'm coming up to an intersection and I see someone edging out, so I slow down and prepare to panic stop in case they pull out in front of me. They don't, so I proceed. That's good defensive driving, but a failed prediction.
I see someone with their signal on in the next lane, so I back up and give them some room to move over. Turns out they just forgot their signal was on. Again, good defensive driving, but an incorrect prediction.
People don't break the rules in anything like a consistently predictable manner. Not around here, anyway.
Noticing some behavior and thinking of all the possibilities is not predictive behavior. What you are doing is making a reaction based on the action by another driver.
In one case, you notice a driver edging forward, so you slow down in case they pull down. If you were predicting that they were going to pull out, you wouldn't just slow down, you would slam on your brakes.
In another case, you notice a driver with a blinker on, so you assume they are changing lanes, and slow down to give them additional space. This one is closer to a prediction, but in reality a driver would notice the blinker before they get anywhere near the car in question and would have plenty of time to tell whether it's a forgotten blinker or a conscious attempt at changing lanes. Or they don't see it from far away because traffic is moving very fast and/or is very heavy, so they just keep going making the prediction that the car w/ a blinker on will wait until the lane is clear (aka after you pass them) to change lanes.