You might remember the meaning of the character 对 with this easy mnemonic:
An issue that pops up again (又) and again when I talk to my American friends is they think in fahrenheit, inches (寸) and feet. Not saying who is right or wrong here but conformity with the rest of the world is more practical right?
Using mnemonics to remember the meaning of Chinese characters like has a huge impact on how long to learn Mandarin it takes.