In a few hours it will be Pessach (Passover). We've been cleaning for weeks, hunting and destroying all vestiges of chametz (bread, yeast, etc), in the Jewish version of Spring Cleaning. Thank God that's behind us!
A thousand years ago or more, a sack of legumes in Europe was found to contain - horror of horrors! a few grains of wheat. Immediately, the local rabbis added legumes to the list of forbidden food for Pessach. The Sephardi rabbis, meanwhile, didn't loose their cool, and moved on to the next sack. Thus was born one of the more significant differences between Ashkenazi and Sephardi Jews: that the Ashkenazi ones eat very little over Pessach, while the Sephardi ones do without bread but mostly get on with life.
A thousand years later, the divide has broadened far beyond what anyone could ever have imagined. The Sephardi Jews (about half of the Israelis), are busy using modern food technology to invent yeast-less alternatives for just about every food product you can think of except whole wheat bread, to the extent that Pessach for them is no more bothersome than a mild itch.
The Ashkenazi folks, meanwhile, have taken the opposite track. Legumes, you see, have derivatives. Vegetable oil, for example. So any food with vegetable oil must be prohibited, obviously. Vegetable oil has its derivatives: sardines, for example, which are canned in it. OUT! CHAMETZ! Modern food processing being what it is, the danger of legume derivatives is, however, far worse even than that. Many types of cheese, for example, are processed in factories within sight of roads on which drivers may travel with sardine sandwiches in their glove compartments: HA! NO CHEESE!
I spoof you not. The art of derivatives of derivatives of derivatives which recently brought down the world economy could easily have been foreseen, had anyone given it any thought, by observing the sheer idiocy with which we Ashkenazi folks root out any shades of memories of that unfortunately poorly packed sack of Humus somewhere along the Upper Rhine in the year 867 Anno Domini.
Chag Sameach - Have a fine holiday. Easter, too.