I rarely look at the speed limits. I always ride or drive much faster than the speed limit, except when on the car and with heavy traffic.
For example near my house I am doing 3x the speed limit (120km/h on 40km/h zone), especialy at night driving the car, or day with the bike and open road.
The car might be much slower, but I am much more at the limit with it, sliding through corners, crazy overtakes, really fast through villages etc. The bikes limit is hard to get, but I enjoy the instant acceleration, usually up to around 110mph on local roads. I tend to be more careful with the bike, when theres trafic.
But in general, even thought I do some dangerous stuff with the car, I tend to limit my speed depending on the conditions, for example during the day when riding or driving by a school I tend to be slower than most, then at open roads at night much faster.