Andy and Alice Atkins and Bill and Bertha Brown are two shipwrecked couples who wash up on Happy Island. They discover that the four of them are the only people on the island (about twice the size of your prototypical desert island in an appropriately chosen Far Side strip). In their explorations they find a single coconut tree, which produces four coconuts a day (the amount of rain and sunshine are very stable on Happy Island, and the coconut tree always gets just enough light and water produce exactly four coconuts a day, indefinitely). There is also a handful of random sticks, branches, and fallen palm fronds on the island. Otherwise, Happy Island is just a mound of white sand in the middle of a peaceful ocean.
The four Happyians (as they decide to call themseves) want to be fair with each other, so they agree to split the fruit of the tree up so that each couple is entitled to half of the coconuts. This works out to one coconut per person per day (it should be noted that these coconuts are so large and rich in nutrients that a single coconut is more than enough to meet an adult's daily dietary requirements). They also split the miscellaneous debris equally between them; there is enough that each of the couples is able to fashion a comfortably medium-sized hut.
Andy and Alice take a liking to their island paradise, and they are happy to enjoy each other's company and the solitude. They go to one side of the island and make sandcastles together, eat coconut together, sunbathe on the beach together, and frolic in the surf together. Andy and Alice are happy to have half of the island to themselves. They don't want anything more; they are content to just be left alone.
Bill and Bertha are a different story. They end up feeling very lonely, and, having between them one complete set of all the necessary plumbing to do so, they decide to start a family. Soon, they have a little baby boy Bobby. As little baby Bobby grows, their medium-sized hut seems a little cozier, and the coconut meals don't fill everyone up as much as they once did. But Bill and Bertha are much happier with their son's company than they were before. It isn't long before they decide to have a second child, and soon little baby Betty is born.
Betty grows fast, just like Bobby did, and the hut really starts to feel small. Everyone goes to bed feeling a little bit hungry; after all, two coconuts for four people doesn't make for large meals (not even when they are as large and rich in nutrients as the Happy Island variety). Still, Bill and Bertha aren't quite satisfied yet. Not nearly so! They decide to have a third child... and a fourth... and a fifth.
When little Bradley, Bonnie, and Blair are born (in that order), Bill and Bertha love them all to pieces - they are precious little bundles of joy, each and every one of them! But they also come to the realization that their medium-sized hut is much too small for a growing family of seven. More importantly, they realize that two coconuts is simply not enough to sustain seven people in good health. As the children get older, they know the hunger will only get worse.
Meanwhile, every day, Bobby and Betty look across to the Atkins' side of the island, trying to understand why Alice and Andy each get a whole coconut every day, and why they have such a spacious hut - nay, mansion - to live in. Bobby is naturally gifted with a mind for math, and by his calculations, if the Atkins were to give just one of their coconuts to the Brown family, why, Alice and Andy would still have more to eat than any of the Brownses. Betty (no less gifted than her brother in the arithmetic arts) can't help but run a similar calculation on the Atkins' hut. Why, if it were just half the size, they would still have more space per-capita (a big word for little Betty, but somehow she managed it) than Betty's family.
Something was wrong with the picture, and Bobby and Betty knew what it was: It just wasn't fair.
Things were likely to continue this way on Happy Island, but fate suddenly intervened. Yes, gentle reader, by a bizzare string of consequences (not to be explained here), You have ended up in charge of Happy Island's future!
So, think long and hard. How shall The Legend of Happy Island end?
Only You have the answer!