Explanation
This is a memory sentence to help you remember how to spell MNEMONICS itself. Take the first letter of each word (the last word, "ClueS", gives both the C and the final S): My Never Ending Memory Only Notices Incoming ClueS → M-N-E-M-O-N-I-C-S. The second version above spells it out the same way, one clean word per letter: Mnemonics Neatly Eliminate Man's Only Nemesis - Insufficient Cerebral Storage → M-N-E-M-O-N-I-C-S.