萬古千秋

万 = 丆 + ㇆ : As mnemonic symbol I choose a neuron, since each neuron is said to connect to 10000 others.

万 = 丆 + ㇆ : Willy Walrus needs to dig up the floor in the anthill's bathroom, but he is tired of doing so manually with a plough. To make his life easier, he sets up a wind wheel for electricity, connects a neuron to the wind wheel and the plough to transmit the electricity and uses his new DIY electric plough to dig much faster.

古 = 十 + 口 : Mnemonic symbol: at least on German maps, this character actually resembles a cloister.

Oh no! Gitta Giraffe (gu) found that the golden cross (十) broke off of the cloister (古) in the space station's living room (Ø3)! She skewers a mandarin (口) on top of the cloister so that she can skewer the broken off cross back on to fix it.

千 = 丿 + 十 : Mnemonic symbol: a 1 kg weight.

The Queen of Hearts (qi) dropped a kilogram (千) on her banana (丿) in front of the anthill (an1), and now she uses a cross (十) to try and revive it.

秋 = 火 + 禾 : The Queen of Hearts (qi) celebrates autumn (秋) by offering sacrifices. She puts a bowl of cereals (禾) onto a swing (秋) and has the cereals swing into a fire (火) in front of the outhouse (ou1).