The one thing that I think I will remember from psychology five years from now are the six scientific thinking principles. The six scientific thinking principles are ruling out rival hypotheses, correlation vs. causation, falsifiability, replicability, extraordinary claims, and Occam's razor. The concept of these six principles has been reiterated throughout the whole textbook so I have become very familiar. They are basically glued into my mind at this point. These principles go beyond psychology and I think that these things can apply to many different situations in life.
For example, somebody might make a comment saying "the beach is packed because it is sunny," which relates to the correlation vs. causation principle because one thing may not cause the other. It also could relate to ruling out rival hypotheses because an alternate explanation could be because it's on a weekend and less people have to work.
Another example is in court cases. The persecutor might make a claim that the defendant is guilty. In this situation they would have to see if the evidence is as strong as the claim made by the persecutor. This relates to the extraordinary claims principle.
With that said, I think I will remember the scientific thinking principles because they relate to many situations in everyday life.