Czech language has thousands grammar rules and millions explanations of them. A lot of czech people have problems with written Czech. In my view, explanations would be totally useless for a learner of Czech. In my experience, a lot of explanations and grammar are obstacles to language learning.
I only remember two rules in Russian, 1) that animate nouns have the same ending for the accusative singular as the genitive singular and 2) that the case for a) one of something, b) two,three, and four of something, and c) five and more are of something are all different. I cannot remember what the cases are, but I have heard and seen odin god, dva goda, piat let, etc. so often that it sticks.
What’s a Flying Spaghetti Monster??? LOL
The flying spaghetti monster is a term used sometimes by athiests to make comparisons and show the irrationality of a belief in God.