A couple of weeks ago, the right headlight in my car burnt out, so I went to the garage and had it fixed. When I picked up my car, their salesnerd told me to watch my left headlight, for "once one headlight burns out, the other often follows in short order".
At first, I found that statement a little odd. But indeed, last Friday (14 days since the previous blowout, 8 days since repair), my left headlight burned out.
Was I just unlucky and the salesperson's tale is just superstition, or is this phenomenon an actual thing?
If so, what causes it? Uneven load/voltage issues?
For reference, my car is a 2013 Kia Rio UB.