Do you keep a record of your training? If so in what in format does it take, written or electronically? There are many methods of recording training including Strava and my favourite, the old-fashioned method of pen and paper.
After training record details about the session undertaken, weather, the training environment, whether you were in a group or running solo, and the subjective elements such as how the run felt.
Over a period of time you will build up a valuable resource that will help you to spot trends in training and racing and a point of reference for specific session or a race such as the London marathon. It may also help the physio when you next go with a niggle. When I look back at some of my training diaries, they refer to a world which no longer exists. For example, measuring a 10 mile route in my Vauxhall Chevette and using the milometer to identify the mile markers – those mile markers acted as a point of reference for many years.