I started out with a bike computer that didn't have cadence. The bike shop said it was for racers, not someone like me.
So off I went on my bike. I had no clue how to shift, when to shift, why I would want to shift. I just rode and mashed the h@ll out of my pedals. Rode with low cadence and just mashed even harder and faster to get more speed on the bike.
Then 6 months into riding I had such accute knee pain I couldn't even pedal. I never got knee pain like I had from riding...from running!
I then learned about cadence. I learned that if you can keep a high cadence of 90-100 you will save your knees. Great!
So I got a new bike computer with cadence and focused on keeping my cadence between 90-100. It was hard but I finally got use to it.
My knees got better... and I got faster on the bike. I also learned WHEN I needed to shift! 80 cadence? Better shift to make it easier. 110 cadence? Better shift to make it harder.
After that it all just clicked. Honestly, I can't believe it took me a year to get it to click. I was a slow learner. And someone told me that cadence was not necessary. But for me, it made all the difference in the world.
Good luck on whatever you decide!
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"