I'd recommend continuing with some of her shorter stories. Isn't "Too Much Happiness" a longer piece about a woman mathematician? I read it quite a few years back, and all I remember somewhat well is its placid, nostalgic tone and unhurried pace, and that it seemed lacking in what we usually expect in a story arc. It seemed half a profile of this woman and half fiction, getting into her emotions in a sensitive way. Munro toward the end of her career (I believe she has retired) began to write fiction that was partly also memoir. "TMH" has a similar feel to it, for me, although it's not Munro's experience.
I like her stories very much. The plots don't stick with me, because they're not plot-centric. She doesn't do a lot with incidents, going more for the interior lives of her characters, but not to the extent of someone like Virginia Woolf. I wouldn't say that profundity is necessarily what to expect from her, either. Try the story about the goat, "The Runaway." Also, "Passion," "Chance," "Silence." and "The Bear Came Over the Mountain" (made into the film "Away from Her"). I didn't remember those titles off top of my head except the last one. I read the first few sentences online and then started to remember those stories. I haven't read all of hers, but your question makes me want to. I suspect I like her early and middle stories better than her later ones.
Do you have a short fiction writer you especially like?
Edit: I had forgotten that "TMH" was the title of the volume, so I thought you were commenting on that story. The brief summaries of the stories rang a bell. I would say that they are pretty typical of what Munro is about, so perhaps your taste goes in other ways, but I'd still recommend sticking with her for a while, and trying a few in other collections.