If you are a human being you should be stretching. Stretching is the absolute bare minimum that you should be doing physically, every single day. You may not want to run, fine. You may not want to walk, fine. You may not want to workout at all, that is your choice. But stretching is non-negotiable.
First and foremost, do your own research on stretching. You are going to see me say that a lot for a couple reasons. One, it is important to do your own research, you don't know me, I don't know you... what I am trying to say and to motivate you to do is certainly in your best interest but you can't rely on that so make sure you do your own research into topics like this. Back to what I am trying to say, your muscles tighten up when you sleep, you are motionless for 8 hours. Then you get out of bed and go about your day. Perhaps you stretch your back when you wake up but you aren't made of just your back. Personally, that back stretch when you get out of bed is a feeling like no other, but when you move around a little bit get the muscles warming up and then spend 5-10 minutes stretching each individual part of your body, you will wonder why you weren't doing it before hand.
It's important to move around when you first get out of bed before you stretch. You don't ever want to stretch "cold" muscles, or muscles that do not have maximum blood flow and have been essentially motionless for the last 8 hours. My go to is to go up and down the stairs a couple times, maybe jump around a little bit and then I will go into my stretches.
I focus on...
Trunk/Core
Neck
Shoulders
Arms
and most importantly legs and feet.
I have 2-3 different stretches for each of these categories, I hold my stretches for 10-15 seconds at a time. If I am particularly stiff on any given morning I may do mine twice. Start stretching, it is something you will not regret, especially when you are in your 50's and 60's.
SK