Yes. As an average consumer, you don't have to care about graphs. But, since there is no place to audition earphones, it will save you time and money by learning about FRs. Most of the time, we can infer how a headphone will sound by looking at the FR which can help you to decide whether to buy it or not. Research has shown (blue line in my graph) is what people preferred on average. So, a FR of a headphone which looks like the blue line will sound nice.