Good point! I think I mentally chucked it with the square knot under "knots that should already be in most people's inventory" but you are right, that is definitely worth learning, since there are so many useful variants.

So like, 4 essential knots: Figure 8, square knot, bowline, hitch. The map, filter, fold, and reduce of knots, if you will. Most everything else can be composed from those.