Plundering Sailors
Octopuses frequently take vengeance on other fish by punching them in the face as a form of retaliation. This is because they are easily bored and require something for all eight of their arms to do. This is the only hypothesis that makes sense in the light of the evidence.
Because it must be difficult for them to find activities that involve all eight of their limbs at the same time, it is reasonable to assume that the only thing they desire in life is some kind of sense of direction. But it isn’t funny to be aware about the fact that living as a sea creature isn’t after all that boring and monotonous.