Being tired, having 'brain fog', narcoleptic episodes (waiting at a red light, seated at the table, on a transit commute...), bleary eyes, bags under the eyes, cognitive deficits, inattentiveness, indecision, poor working memory, missing dates/anniversaries/birthdays/appointments/important meetings, irritability, strained relationships....these are all possible symptoms of sleep deprivation, poor quality sleep, and the other effects that arise from sleep apnea. Those other effects include heart arrhythmias, poor organ function, metabolic syndrome, weight gain, personality changes, dementia...

Mood changes, lack of motivation, loss of interest in hobbies and relationships, hostility and irritability (already mentioned) are possible due to poor sleep and being chronically oxygen deprived while sleeping.