We've always got used to speed pretty much as quickly as manufacturers are able to find it. Four decades ago a mainstream car that could get to 60mph in under 10 seconds was considered seriously rapid. These days a diesel-powered repbox can do it in eight flat.
But in recent years, the rate of progress has got spectacular - maybe even silly. It was a point brought home by the recent filming of our GT-R versus GT-R video.
Ten years ago, the 'R34' Skyline was one of the first real performance cars I was lucky enough to try as a journo. I'll never forget my first serious drive in one, through the twistier bits of mid Wales, for two reasons. Firstly, the sheer, physics-bending capabilities of the brutish Nissan, secondly the fact it coincided with the day of the solar eclipse, giving a suitably other-worldly feel to proceedings.
A decade on and, driven back-to-back, the 'R35' GT-R really does make its predecessor feel - if not exactly slow - certainly as if it's barely in the field adjacent to the ballpark on straight-line pace. The GT-R has getting on for twice the firepower and an even-cleverer array of differentials to deliver everything to the tarmac, but I was still slightly shocked how a car that was once a performance benchmark now feels so deflated, in terms of pace if not raw experience.
But things aren't going to carry on developing like this. Put simply, they can't - the writing is already on the wall and I reckon that in another decade cars like the GTR will be regarded as the high water in terms of raw speed. The challenge now is to maintain performance levels - or something close to them - while delivering on CO2 and fuel consumption reductions.
From the point of view of enthusiasts everywhere, here's hoping someone manages it.