I'm not sure what it is, but talking to computers just makes me wig out. I get extremely self-conscious, wondering who is listening or might hear me. This doesn't happen with humans on the other end.
Saying "Alexa 5 minute timer" is also convenient. "Alexa, weather" is less convenient because she doesn't know that I prefer Celsius over Fahrenheit. This is unfortunate, but at least she can do a conversion.
But then you do an "Alexa what's the velocity of an unladen swallow" and she won't even perform a basic Google or WolframAlpha search and give you the first result. Just says she doesn't understand. Lame.
Before all that, though, I had a lot of essentially stage fright whenever that Alexa blue light came on.
Same thing happened when I started using Siri after I was already used to Alexa. Invoke the voice thing, and the prompt comes on, and I am awash in stage fright, unsure what to say.
It's weird.
There's a device-level setting in the mobile app to set Alexa's preferred system to Metric...
Or I'm growing senile and didn't actually try that when i thought I did.