If there's one thing we know as modern people with modern sensibilities, it's that symmetry is grossly overrated. Sometimes, a little bit of asymmetry may just save you a lot of hustle. Take these earphone caps, for example; if you switch one of your earphone caps with a spare cap that you saved from a different pair of earphones (for instance), you'll be able to tell apart right from left, no problem.
Also, saving your earphones is just generally a good idea. Earphones tend to shed their silicone caps for some reason, so you may just want to keep a few extra pairs around your house.