于事无补

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.

事 = 𠮛 + 彐 + 亅 : Mnemonic symbol: The thing.

事 = 𠮛 + 彐 + 亅 : Sherlock Holmes read a magic scroll in the bathroom of the space station. The scroll promised eternal love to anyone who reads it and wears a pig's nose while doing so, and Sherlock gave it a try. Now he summoned the thing, and he is scared to death! All he has to defend with is a crowbar. However, he never was in danger: Since he is wearing the pig snout, the thing thinks Sherlock is his mommy, and it just wants to cuddle.

无 = 一 + 𠂇 + 乚 : Mnemonic symbol: the philosopher Diogenes, who has nothing and wants nothing.

无 = 一 + 𠂇 + 乚 : Just inside the space station's entrance, Diogenes is annoyed by Willy Walrus, who's playing his flute. Diogenes just wants a peaceful time without being disturbed, so he cuts the flute into pieces with a pair of scissors, and threatens to beat Willy Walrus with a shovel should he annoy Diogenes again.

Mnemonic symbol: 無爲, wu2 wei2, the state of non-doing after having attained complete harmony with the Tao.

Willy Walrus (w) has attained Wu Wei (無) just inside the space station's entrance (Ø2), while from the outside it may seem like he is napping.

补 = 卜 + 衤 : Bruno Bear (bu) broke his voodoo staff (卜) inside of the space station (Ø3) and he has nothing available than a royal ermine coat (衤). His staff means much more to him than the coat though, so he rips the royal ermine coat into stripes to fix (补) the staff with the stripes used as bandages.