to be stupid / to cheat or deceive / me or I (modest)
愚
=
心
+
禺
:
禺狨王 (禺) gives Yu the Great (yu) his heart (心) in the space station's kitchen (Ø2). Yu the Great is very moved and just as she is about to take it 禺狨王 snaps it away, exclaims that it is just an April Fools' (愚) joke and calls Yu the Great out on how dumb (愚) she is.
孝
=
⺹
+
子
:
Mnemonic symbol: a mourning veil. Marie Curie (xi) was breeding an egg (子) in the aorta's bathroom (ao4), and she even put a crown (⺹) on it (the crown is on top of the egg: 孝), so much she loved her little prince. Unfortunately the egg died, and thus Marie Curie put on her mourning veil (孝).