Is it just excellent observation?

I'm currently reading Anne Enright's 'The forgotten waltz'.

There is a chapter when she describes lying in bed, hearing her man get up to pee.
We've all been there, done that, heard the stop start, and the sigh, heard the cord of the light switch bounce on the mirror, the slap of the feet on the floor.
Is that why it, her writing, has such power - because we recognise and share, glad to have our inner selves confirmed as being normal?

At that light switch level I could do this too - but am in a way reluctant - scared, maybe, of boring my imagined reader with mundane (but she is not mundane!)   

She describes love and death, sex and arguments, much of which I also recognise, but I am far less confident that I could write it, fearing that in doing so, in describing something which I am having, from the paucity of my experience, to make up, to pad out with my imagination, I am getting it horribly wrong.