What does the man mean?

W: I don’ t think the job has to be done perfectly.
M: Maybe, but it’ s important to do your best.
W: Yes, maybe you are right.
M: Just do your best.

W: Do I need to take some medicine?
M: Yes. And I strongly advise you to go on a low-fat diet.
W: Do you really think that’s important?
M: Definitely. If you don’ t, you might have a heart attack some day.
W: Well. I think I should take your advice. You have been very helpful. Thanks.