This evening I had a different occasion for telling the story. While visiting Geo and Krissy, their Czech friend came over for supper. I had to tell her the one Czech phrase I remembered: Ja jedli šneci. I recited it, then asked her if she knew what I was saying. After looking at me like I had three heads, she tried to puzzle it out. In the end, I had to tell her what I was trying to say.
Because she didn't offer the response I had hoped for ("Oh, my gosh, you know how to speak Czech!"), I asked how to say "I ate snails" in Czech. She told me the proper sentence was, "Ja jsem jedl šneky."
It turns out that the phrase I had learned four years ago actually meant something like, "I am we having a snail." That's pretty close to "I have three heads." If I had recited that to a Czech paramedic during a bout of anaphylactic shock, I'm not sure I would have received the care I needed.
What I should have said? Ja jsem jedl šneky.
Thank God I'm not allergic to snails. Thanks, Simona!