When "I" think I need one...I can't remember the last time I was sick...I grew up with lots of Doctors in my family and worked for Doctors...honestly, people go too much, not always in their best interest. I'm a big believer of walking, and taking lots of different Vitamins. This is me...I don't advocate what I do to anyone else.
In the past, I had a check up as irregularly as possible. Now that I have been diagnosed with a (benign) brain tumour and NF2, I see my GP every other week. Once the various specialist and surgeon's appointments get rolling after Xmas, I expect that it will become at least a weekly event.