The importance of stretching

I’m very sure if you do sports on a regular basis you already read and heard a lot of times that warming up before and stretching after the activity are very important. I’d like to share my recent experience that taught me they really are and I should take them seriously.
In November, the weather here was around -5 ˚C. My runs were not long, 8 km top, but I always rushed. Closed my notebook finishing the work for the day, gear up, run, take off the dress, be with the family. What can go wrong? Nothing, if you are 20 years old. But I’m over 35.
At the end of November, going down the stairs was very painful. I felt something between the shin and the calf on the inner side of my right leg. Even walking wasn’t comfortable, not that much as climbing the stairs, still, I felt it. What I did? Rest and tried to give it proper massages with an SMR foam roll. It got better after a week, thought it’s all over, I can go and run again; but I was wrong. After the 3rd km it was painful again and the next day I barely managed to go down on the stairs, again. Due to the COVID situation I didn’t want to visit a doctor nor a hospital, I decided I’ll rest my legs in the whole month, won’t run, and before I go to sleep cream with comfrey and use a bandage. At least I can get ready for Christmas.
Between the two holidays I had a discussion with my neighbor who I usually run with and he asked how’s my leg doing, can I run? I told him that it got better, however I still feel the pain when I walk. He had injuries earlier and knows a physiotherapist, told me I should visit her.
In the beginning of the new year I went to the therapist, explained since when I do sport (and what kind of them), plus since when I run. The first question she had was: “and how long you stretch after every run?”. Well, about 1 minute. She did some examination and concluded my calf is stuck so much on my sin that it can’t move even a bit, I must massage the calf off the bone, and buy a massage ball to soften the muscles I didn’t care about through the years.
I had a checkup today, on the 10th of February, so more than a month passed by for now. I can walk, go downstairs without pain, run 8-10 km without being worried I can’t go further, but I must still stretch and foam roll my legs, and I think it will be a long way until I don’t feel anything while I have an exercise.