Ayumi does play a big part in my life because music plays a big part of my life and since Ayumi is a huge part of the way I view music... well, you can do the math.
Also, when I spend time with my grandmother, we watch videos, listen to her songs (even sing along) almost daily. She always says how Ayumi changed her world too. My grandmother, as a pretty emotional person, has also cried quite a few times because of lyrics (A Song For XX), just because of the song (Born To Be...) and because of the emotion and power in her performances (SURREAL at A MUSEUM, SURREAL at Dome Tour 2001).
I even wrote an essay on music with the main subject on how Ayumi changed my musical understandings and I got a perfect 10 for it.