Completing my jigsaw puzzle

I have a dream that I would like to develop into a doctor with a wide-ranging and comprehensive knowledge by the time I am sixty.
Some twenty years ago, I became a doctor. I trained to gain as much knowledge as possible because I wanted to be a local practitioner in the future. However, the hospital where I worked did not have a curriculum to specifically train to be a family doctor. Trainees therefore had to select their specialty. I chose pneumology, meaning specialization in the respiratory system. However, as most of my patients have thus been people with respiratory diseases, my territory has been restricted. Many doctors in Japan have similar careers to me.
I went into my own practice eight years ago. However, when patients ask me various questions, there are still many aspects where I cannot be satisfied with my answers even now. It could thus be said that it might be ideal that we should start our practice after getting a more thorough knowledge which would allow us answer more comprehensively. However, I think that it is impossible to gain all medical knowledge, particularly as that is expanding enormously.
If I try to compare a brain realizing everything to the completion of a jigsaw puzzle, my brain before I started practicing was like a jigsaw puzzle that had only one finished part, about pneumology. I am filling the jigsaw puzzle of my brain piece by piece by means of not making light of the questions I am continually faced with and solving them properly. However, I have a long way to go until I finish it. My dream is that I can complete it by the time I am sixty.