That's an underlying issue (PEBCAK) which can be mitigated with mindfulness. The same could happen with an abundance of p&p notes. Someone who claims it doesn't happen w/their p&p notes, why would it happen with digital ones? Because the storage is easier and accessible (cloud in on your mobile in your pocket)? But an agenda full with notes isn't hard to carry around. My mother has been doing that for ages. She writes her passwords in her agenda, for example, and she still can't find them because its not well-logically mindfully structured. That wouldn't be solved by digitisation. Its PEBCAK all over.