Cynicism has left the old man all alone, he feels loneliness for the first time( I guess) at the age of 74, he is a doctor with 50 years of service now. Now he finds that he is all alone. His fiance left him when he was young to marry a brother of his. His knowledge, the doctor's intution is failing him now. He realises he has done no good for his son. He is guilty of neglecting his wife, being too cynical. He is guilty of being stone-cold towards his mother.
I hope people don't need to turn 74 to realise what they have lost out on at any point of time. An achievement is all but a moment. There are so many moments of happiness which one need not sacrifice for a moment of glory. But well, taht might be my priority and people do have different priorities. When all things fail you, it is the people around you, the goodwill you have built for yourself that shall stay with you forever. (shown in the movie)