You might remember the meaning of the character 熟 with this easy mnemonic:
I am highly skilled in putting a lid (亠) over the mouth (口) of a child (子) , or slashing (丿) their toys if they make the same mistake a second time (乙), like putting firewood with strange dots (丶) on them when kindling (灬) fire.
Using mnemonics to remember the meaning of Chinese characters like has a huge impact on how long to learn Mandarin it takes.