The moment when you realise you've possibly been taking medication due to taking your blood pressures wrong for a year.
I've been reporting my blood pressure to my GP as being a little high based on taking the measurement about 30 seconds after sitting down, based on observing how quickly nurses took it after I sat down when first diagnosed as diabetic.
And I have my legs crossed a lot of time, and sometimes recently now I've lost weight I'll sit in the yoga position with both legs crossed on each other while waiting for the machine.
Oops.