老于世故

老 = ⺹ + 匕 : Lancelot (l) is showing his respect to grandpa (老) in the aorta's living room (ao3). He's bowing deep and offering a crown (⺹), but grandpa refuses by hitting Lancelot on the head with a ladle (匕).

于 = 亅 + 二 : Mnemonic symbol: prepositions (in, at, on, to, ...) are what glue the sentence together. Honey is as sticky as glue, so I'll represent 于 by a honey jar.

Yu the Great (于) was assigned to repair the electronics of the space station's kitchen (Ø2), but instead he was snacking honey from a honey jar (于). Unfortunately his capacitor (二) got stuck in the honey and now he has to use a crowbar (亅) to lever it out.

世 = 廿 + L : Mnemonic symbol: the WTO or WHO.

Sherlock Holmes (sh) is cleaning a flower pot (廿) under the shower of the space station's bathroom (Ø4) with a loofah (L) because he didn't quite understand a poster next to the shower from the WHO (世) explaining dangers arising from different germs.

In this case, L is for loofah.

故 = 古 + 攵 : Mnemonic symbol: This character only appears in 做, so we don't need a strong mnemonic symbol. We should be able to refer to 故 when we think of 故事 or 故意. Because it fits nicely to its components, I'll think of it as in the meaning of 故墓, an old grave.

故 = 古 + 攵 : There is an ancient cloister in the space station's bathroom, and Gitta Giraffe once heard a story from her fellow astronauts that there's an old tomb inside with lots of treasure. One day she can't hold herself back anymore and deliberately breaks the cloister open using a sledgehammer.