Context : Young woman (American) is (reluctantly because she didn't want to have tea but didn't want to be rude) having tea with an old woman (Irish). the old woman asked her if she would pour them tea.
Book setting : Ireland.
“Will you pour?” she asked primly. “Yes. Yes, I’d be glad to,” I stammered, trying to remember a moment when I’d felt more uncomfortably American. I mentally scrambled for the etiquette, trying to remember what came first.
What does this trying to remember a moment when I’d felt more uncomfortably American. mean? Is she trying to remember the time when she felt more uncomfortable being American that this time she has to pour tea?