Driving as Fast as I Dare

In winter I've noticed a phenomena, at least with my driving.  When roads or slick or conditions not ideal, I drive as fast as I dare.  This could be 35 mph on the Interstate but it is as fast as I dare.  Then, suddenly, road conditions approve and I keep driving as fast as I dare and quickly I'm doing 85 mph on the Interstate (where the speed limit around here is 70).  This happened to me coming back from Portland one time.  I was driving in the Columbia River Gorge on the north (Washington) side and it was very foggy, so I was driving as fast as I dared for the foggy condition which was well under the speed limit.

Then the fog lifted and I forgot to stop driving as fast as I dared.  I think I was doing 72 (in a 60) when the cop got me on radar.  Luckily he didn't give me a ticket (my luck ran out two years ago in June when I was doing 48 in a 35 on a country road that has, in my opinion, a too low speed limit, anyway).

Or, the roads will be bad for weeks so you really get in the habit of driving as fast as you dare, then suddenly they're clear and you're speeding everywhere (because, by and large, speed limits are set too low, anyway).

Other times, during the summer, I drive as fast as I dare and hope there's no cops around.  I'll plead the fifth if asked how fast I go.

Do you drive as fast as you dare?