You might remember the meaning of the character 滞 with this easy mnemonic:
Whenever you feel sluggish, just take these droplets (氵) and put them in one (一) eye. Or you can slash (丿) a line (丨) through the sluggishness by sleeping ten (十) minutes under this cover (冖) and having a beef skewer (巾) afterwards.
Using mnemonics to remember the meaning of Chinese characters like has a huge impact on how long to learn Mandarin it takes.