As I often mention, the best tips are often the simplest!
When I knew why there was a small knot on an earphone, I pulled out miner and I did the same. The reason ?
This is to quickly differentiate the left earphone from the right earphone!
Personally, I use my headphones to chat on the phone when I'm driving. When my phone rings, I always looked at my headphones to see which side is the right one. My eyes then left the road for a few seconds. You know like me that in one second an accident can happen!
This is a safety tip, I only have to touch my headphones to know which one is the left (personally, I tied the left headphone) and I keep my eyes on the road!