Memory problems are common with Narcolepsy. Especially if you have trouble falling or staying asleep. Your brain files your memories in sleep. The more problems you have sleeping the more memory issues you may have. If you are excessively sleepy during the day it's what a lot of us refer to as sleep drunk. Problems forming memories, coordination, unsteady, may walk into things much like being drunk from alcohol, hence feeling sleep drunk. And it does impair cognitive functioning so we should not attempt to drive or handle dangerous machinery when feeling sleep drunk.