I think being competitive also helps. If you have a goal in your mind that you must achieve, you’ll achieve. When I was running, I would keep track of landmark along my route and I would memorize the time that it took to get to that landmark. I found it really helped when I divided my route based on the landmarks and try and beat my time at each landmark.
I am not sure that my memory is as good as yours.
The technology has become much more advanced now, but in the mid 1980s I purchased the first Polar Heart Watch which had internal memory that could record your heart rate at 5 second, 15 second or 1 minute intervals for up to 2 days. The unit was used in both medical settings and by serious athletes.
When you pressed one of the buttons it would record the time. So on my training routes I pressed the button at designated landmarks such as at the bottom and tops of hills and other places that had significance on my route.
At home I uploaded the data using an adapter that plugged into a serial interface on my desktop computer. I had software that I used to analyze and graph this data and to me it was very interesting to see the progress that I made during the season. I designed some of the programs myself. I helped teach a class on Lotus 123’s very capable macro language which was extremely useful for this type of analysis.
Of course, these days there are software packages that work with relatively inexpensive cycling computers with GPS which records your position and altitude and connect to heart rate sensors, speed and cadence sensors and even power output sensors. They automatically record all of this data and upload it to numerous software packages that can analyze everything about your work-out and keep a detailed record.
I have one with a 2.6 inch black and white lcd screen that is visible night and day with built in GPS that I use with three different ant+ sensors (HR, speed, and cadence). It weighs just a couple ounces. It cost $48 on Amazon and has 5 different customizable screens that you can switch between with the push of a button.
A couple years ago most people bought an expensive Garmin, Polar or other name brand cycling computer to get these same features. I used cycling programs for years on a cell phone (the Samsung S5 sport) with the Ant+ communications protocol built in. The battery life using the programs used up the battery quickly; it was hard to see the screen in direct sunlight and it was not as waterproof as advertised.
Now these new Chinese cycling computers are very cheap and they perform pretty well. The sensors are also cheap and interchangeable between different brands.