You probably put to much stock in the whole "I've never been through the imaging machines" bit. It's not about remaining opt-out puritan or something. Fight when you can.

I hope op reads this, buried in all the other comments. Please, for the sake of everyone, dust yourself off and opt out again. It doesn't matter if you do it every time.

I opt out every time I can, but there have been plenty of times when I don't. There's been times when I didn't have time to catch my flight, or my stress levels were bordering on unmanageable, or I didn't want to miss that wedding at any cost. One time, I felt like I had to pee too bad to risk waiting for a screening.

So kick off your shoes, empty your pockets, and take the freedom stance on the mat of defiance. Hold your arms out with pride and hope that someone on the other side of the security barrier sees you and decides to opt out as well.