Earplugs are life saviours, especially during the drab, seemingly endless metro ride or to avoid those awkward hellos when you pass by someone you don't want to make conversation with. It is also one way to effectively filter out all the peripheral chatter and the cacophony of the everyday mundane, when you need to focus. Even night-time easy listening becomes 'easier' when you have a pair of earplugs for company.

Feeling the ridges/perforations also helps you determine which earphone is which, in the dark; so that you don't have to go through the ordeal of switching on the lights

While the ridges are a big help, they still can't save you from the tangled mess!