Earlier quoted context omitted.
You can make due with only a couple of good knots. Very short list: the reef knot (square knot, avoid the granny version) and the alpine butterfly (don't use reef knot for joining two ropes, i.e. a "bend"). The alpine butterfly is more useful to know than the bowline, IMHO. If you want to expand your list a little, here are some additional useful ones: double fisherman's, adjustable grip hitch, sheet bend, trucker's…
Right, but this isn't a what question, it's a when to do what question. I might know a knot, but I don't know when to use that knot and when it ought to be avoided. That's what I am getting at. Even under the "bend" page in Wikipedia, sometimes the knots are merely described.
I think a flow chart of when to use a knot is a great idea! Please make it!