不
=
丆
+
卜
:
Bruno Bear (bu) is setting up a wind wheel (丆) with a voodoo staff (卜) in the space station's bathroom (Ø4). He also puts a "forbidden" sign (mnemonic symbol for 不) on it, to make clear that it may not (不) be stopped.
知
=
口
+
矢
:
Mnemonic symbol: Francis Bacon is attributed to have stated "scientia potentia est", "knowledge is power". I'll thus represent 知 by Francis Bacon. Francis Bacon (知) and James II of England (zh) are playing darts (矢) in front of the space station (Ø1). Because they lack a dart board they just use a mandarin (口).
to go forward / to advance / to go in / to enter / to put in / to submit / to take in / to admit / (math.) base of a number system / classifier for sections in a building or residential compound
进
=
井
+
辶
:
Joan of Arc fell into a well after she entered the encampment's bathroom, but luckily one of her gladiator sandals got stuck on one toilet, so now she can use the string to climb out of the well.
to retreat / to decline / to move back / to withdraw
退
=
艮
+
辶
:
Tommy Turtle (tu) recently retired (退) and retreated (退) into the Eiffel Tower's bathroom (ei4). There he just wears gladiator sandals (辶), blows chewing gum bubbles (艮) and ponders the sense of life.