I love film for many reasons but the element of surprise is what has hooked me. You never know what you're going to get. When I was out shooting with Kate, I picked Portra 800 and I always shoot this film at 200 ISO because I love the colors it gives me at that exposure.
However, and this happens a lot with me (the forgetting part), as the light was getting dimmer, I forgot to adjust my shutter speed and effectively shot this at 800 ISO. When I was rewinding my roll I realized I had been off a few stops for the last shots and cursed myself for my mistake.
However, it turned out to be my favorite frame of the shoot. I love the deeply saturated color and creamy skin tone. I still make these mistakes but instead of getting frustrated, I smile in anticipation of what the film gods have in store for me.