亻
=
丿
+
丨
:
Mnemonic symbol: Rosa Luxemburg. She's quite radical, and her name starts with "r", just like "ren2". Also, 亻appears at the left-hand side of characters, and Rosa is a leftist as well.
Robinson Crusoe (r) and Rosa Luxemburg (亻) are having their favorite snacks in the encampment's kitchen: Rosa is eating a banana (丿) and Robinson is eating a dinosaur bone (丨).
单
=
丷
+
田
+
十
:
In front of the anthill there are many, really a field of crosses because Don Quixote killed so many people on his crusades. Today is his judgement day: a mean crocodile reads the list of his victims to him, and Don Quixote is really 不好意思.