One time, I successfully got through security with a boarding pass from the same flight two months earlier. It turns out that I accidentally pulled out the old boarding pass from my carryon. It wasn't caught until it beeped at the gate and, even then, the GA didn't realize what happened. She just thought that the computer had printed the wrong seat assignment somehow. She crossed out the seat assignment and printed the new one on the boarding pass.

It wasn't until I got on the plane and looked at the boarding pass that I figured out what happened. The funny thing is that the TSA screening area was not at all busy (only 2 or 3 people in line) and the TSA agent carefully scruntized my boarding pass (putting checkmarks by all the relevant info including the wrong date).

Back in the day (before ID was checked), errors like the OP's happened a lot particularly to people with common names. They would often get sorted out on the plane (or never sorted out).