Can't tell when i had conversation (today/yest./earlier in wk?). this happens often. have apnea/use cpap nightly. could this be a sign of trouble?

Check CPAP settings: The epworth sleepiness scale is a screening tool to see how sleepy you are as this may affect your memory. It is possible that your CPAP may need to be adjusted and you could get a CPAP titration to check if your machine is optimally set. Also consider trying a different mask, have machine serviced. Consider brain/neuro consultation with a neurologist or your regular doctor.