Spent 5 hours chasing a light leak that turned out to be my own thumb

Shot a roll of Portra 400 through my Canon AE-1 at a car show in Austin last weekend and every single frame had this weird orange smear on the left side. I was sure the seals were shot, so I ordered a foam kit online and watched 3 repair videos before it even showed up. Then I loaded a test roll and the smear was gone, and I felt like a genius for about 10 minutes. Loaded another roll, shot 12 frames, and there it was again. Turns out I was holding my left thumb right over the edge of the film door and the light was sneaking past it on sunny shots, 5 hours of my life gone. Anyone else ever blame their gear for something that was 100% user error?