Although Jobs didn't die of a "man's disease" there are lots of men killers out there that can be stopped if you look for the signs. But talking to men around me we are often reluctant to go and see a doctor for regular health checks.
If you have a smoke alarm in your home, it's not because you expect a fire, but because you want to be warned if there is one. Think the same way about your own health: a visit to the doctor for an annual medical is a smoke alarm for your body.
PS In the UK if you are over 40 then the NHS offers a free "Health Check" (http://www.nhs.uk/Planners/NHSHealthCheck/Pages/NHSHealthChe...) that screens for common adult diseases. It's free. Go do it.