When I was 15, I had to go get some (in retrospect) minor injury checked out. The ER where I went, as part of procedure, checked vital signs.

They (without realizing it) used a blood pressure cuff which was too small, and thereby created a false-high reading.

As a result of this false high reading, a trip I had been planning for months, to London, was cancelled, and I spent my break going to medical appointment after medical appointment, only to find out that there was nothing wrong with me, but that the initial and subsequent BP readings were done with a cuff that was too small.

Thin privilege is avoiding health scares, and being able to go to London.