You can remember the meaning of 等等 with this easy mnemonic:
I hate going on group tours, if someone is late, we'll have to wait (等), and if someone gets lost, we'll have to wait (等) for them, try to find them and et cetera, its just too much of a hassle for me.
Using mnemonics to remember the meaning of Chinese characters like can have an enormous impact on how long to learn Mandarin it takes.