In many of posts on this subject I see a stated or implied reason for
the pilot's declining performance as being age related. While I would
agree that age is a significant factor impacting one's mental
sharpness, I think we all need to be aware of other factors that may
lead to impairment. Just because your birthday cake doesn't have 60 or
more candles doesn't mean you or your soaring friend may not have a
problem. Both stress and illness can play a significant role in
reducing one's mental concentration. You may not connect bad times at
work, a problem marriage, financial woes or a family illness as
negatively impacting your soaring skills but it can and does. There is
no shame (in my book) for skipping the PIC for a while and going dual
during such times. If you see symptoms of stress or health related
problems in the pilots you fly with, I believe it's an obligation for
you to voice your concerns.