How would you recover from this situation?

The ‘voices in my head’ are letting me share this one:

I was in the bathroom stall at my daughter’s day care yesterday afternoon… I had so many things whirling around in my head, planning dinner, picking up the mail for a relative that’s away for a while, packing her clothes for her Dad’s tomorrow… etc…

so while I thought I was “talking” to myself in my head, turns out, I was talking OUT LOUD to myself, just as I was walking out of the stall, one of the teachers looks around me and says, OH< I thought you had your daughter in there with you…
I was mortified so my answer was some incomprehensible mumblign as I brushed past her.
I’m pretty sure she now thinks I’m completely crazy… how do you recover from something so embarrassing?