Weird question. Are you a troll? Would you ask a group of athletes if coordination or speed mattered for their sport?
Having said that, I don't see why we would have to memorize any more (or less) than any other specialty. I math important for ER? The only math I use is to figure out weight-based dosing on drugs. I haven't used calculus, or geometry in clinical practice, so you can stop sweating it if you aren't great on those topics.
A common joke that hurts a little too much to be very funny is, "In ER, the only thing you have to remember is where to find the on-call list."
Real life has the benefit of google, a shelf full of medical textbooks, an itouch, and yes, a hospital directory of specialist doctors who have more experience than you in particular areas.
However, the vast breadth of ER is daunting. Go pick up a tome of Tintinalli's (1900 pages of fine-print), and tell me if a good memory would be useful in learning all that material. If you don't have things down cold, you are going to forget something at some point, and mismanage a patient. You don't look for things that you know little about.
Most of the patients, and stream of BS complaints that present to a modern ER don't take a lot of knowledge-base to deal with. However, ER doctors spend 85% of their study time reviewing infrequent clinical presentations, and rare diseases. You are going to be a better doctor with a good memory and triggers that put your feelers up and cause you to go in the back room and read up on a particular topic.
And yes, you will be a better doctor if you actually remember what you have studied.
