For the perplex:

e.g. is latin for "exempli gratia" = for example i.e. is latin for "id est" = that is

As someone who was perplexed, I've only heard perplex used in past tense (I was perplexed) so seeing "For the perplex" just made me confused as to what "perplex" meant and I had to do a further search to decipher this tree of comments haha

A good way to remember it is to use a backronym:

e.g. - example given

i.e. - in effect