The ignorance of the world around those folks who lived 20 centuries ago is staggering comparatively speaking to our understanding today, hence there were probably a great deal of people suffering from all kinds of ailments and diseases back then. Walking on water, raising people from the dead, etc. most likely is based on some kind of mental disorders.
Setting aside the claims of miracles and focusing only on the place in the text where I assume you looked in order to ask this question. Mark 3:21, I think?
Why read that into it? It can be viewed from other angles. It says that he and the disciples were surrounded by crowds and so busy they couldn't even find time to eat. Maybe, it was concern for his health and knowledge of the magnitude of the task Jesus had taken on that caused the comment. I think I'd ask the same question, even if I had seen someone perform what I perceived as a miracle or two over the years. If they suddenly became known to the public and desire to be near them went viral. People change when they become famous. Rarely for the better. You tend to worry.