亶
=
亠
+
回
+
旦
:
Mnemonic symbol: to bow and show how earnest you mean it.
Don Quixote (d) ordered a beer at the bar in the anthill (an3). The barkeeper questions whether or not Don Quixote will return (回) the mug (旦) after he finishes his beer, so Don Quixote bows and shows how sincere (亶) he is by handing over his beret (亠) as security deposit.
tree / wood / coffin / wooden / simple / numb / one of the eight categories of ancient musical instruments 八音[ba1 yin1]
木
=
八
+
十
:
Mnemonic symbol: a Christmas tree. Malte Monkey is putting up a Christmas tree (木) in the bathroom of the space station (Ø4). He's using a cross (十) as a base to put the tree on, and decorates the tree with eight-balls (八).