What if a person reached the age of 46 and was actually an undiagnosed schizophrenic? This person actually had schizophrenia for over 25 years; but never was "treated" because they never had to see a doctor ? The person was able to go through life "undetected" because most of their sypmtoms were "mental" with some tactile and occasional auditory. The mental symptoms were hallucinatory but they kept them all to themself. However, What would happen if the mental hallucinations were becoming harder to control throughout the day or week??
What sould this person do if suddenly someone did notice something different.
Luckily, it seems as though the person you are talking about may have mild Schizophrenia if he or she hasn't had a break-down after all these years. Since it seems like it it starting to interfere with his or her functioning and/or quality of life, it is important to encourage that person to seek help. Most of the time, the symptoms can be effectively controlled with medication and psychotherapy.
It is also important to know that there is absolutely no shame in having Schizophrenia, and especially not in seeking help for it. It is a medical condition. The sooner the person gets help, the better the outcome will be.