One of my team members actually ran out on her lunch break to buy a dictionary. She told me this a month or two after the fact. She needed to look up something I'd written in an e-mail. I apologized for causing her to go to the extra effort--and expense--but she wouldn't accept it. She enjoyed the verbal challenge and the sense that came with it of becoming a more literate person.
Good communication is not always about passing the message in the optimal way.
This knowledge comes in handy when reading other peoples' code, but I don't use those instructions myself. Why? Because I know how to achieve the same effect through carefully-scheduled combinations of smaller, faster opcodes.
Exactly the same principle applies in English composition. Use an awkward or unusual word, or a flowery modifier? That's an L1 cache miss. It'll cost a few cycles of wasted execution time, if viewed in terms of the reader's attention span. How about a word that sends the reader to the dictionary? That's an L2 miss. Those can waste thousands of cycles.
You can tolerate a few L1 misses here and there, but those L2 misses that have to be fetched from DRAM will make your "code" run like shit.