I saw the speed limit sign that announced 55, following a long stretch at 75 miles per hour. A short distance later, I saw the next sign indicating 40. What I didn't react to promptly enough was the 25, which I registered simultaneously with the police officer I passed, his vehicle cruising into the road behind me like a shark -- except sharks don't explode in tell-tale cacophonies of flashing light (and if they do, it's better I don't know).
Polite, terse exchange of words ("I pulled you over for your speed." "Yes, officer."), then documents. Short wait that felt longer than it was. More brief dialogue ("As you can see by the sign next to you, speed limit's 25." "I understand, officer." "Just going to give you a warning." "Thank you, officer."), and then back on the road where I matched the posted speed precisely at each change of its pace for the rest of today's journey.