Forgetting doses and taking them twice are both common and both dangerous. Pill organisers, blister packs from a pharmacy, alarms and locked storage all help at different stages.
Non-medical caregivers may usually only remind and prompt, not administer; the rules vary by state.
Why it matters
Medication errors are a leading cause of avoidable hospital admissions in older adults.
Sources
Where to check this, and where to read more. All external and all authoritative.