You might remember the meaning of the character 校 with this easy mnemonic:
A mother confused about a new learning in (aka. LID) (亠) method at her child's school. Calculating the impact of slashing (丿) down trees (木) sounds too advanced for an eighth (八) grader.
Using mnemonics to remember the meaning of Chinese characters like has a huge impact on how long to learn Mandarin it takes.