Or simply different than "average". Individual differences in how various substances impact the senses is a very real phenomenon. I can get to a level where the heat blocks the flavor, but that level is far higher for me than for most other people, it seems. One purported explanation by some is, certain people have the ability to taste at a far greater intensity than others. Often, these people seem finicky/don't like many foods. It is possible the spice deadens a bit of that sense, leaving the taster to more moderated experience of the other flavors. I'm not sure I buy that explanation, as supertasters tend to experience hot at a higher intensity, as well.
Irrespective of the explanation or mechanism, I taste the basil, garlic, fish sauce and various Thai spices in my grapow, even though I have it prepared at a ridiculously hot level.