My worst pinball sin is one nobody can see - when I'm in a groove, having a good ball, and my mind wanders toward the thought of "damn, I'm killing this machine!" And like that, I get careless, especially on fast flowing games where I start firing as fast as the ball comes to the flipper. Instead of catching and timing a shot or thinking about how I might defend if I miss, I'll start making risky redirects and firing fast inlane swooshes on the fly. It feels even better when the first time or two they hit their targets, and it further encourages that gunslinger mentality. It's like being the pinball version of Brett Favre, late in the NFC championship game.
Within seconds, one of these poorly advised shots is a miss, and a drain that was avoidable if I slowed the pace a bit and thought things out better. Every time. Then I will fall into a funk and drain my remaining ball(s) with little to show for it, and waste that one good ball with an average at best final score. That's an empty feeling, even when it's single player noncompetitive play.
I don't get to play real pinball too often. Sometimes I think I fall into the visceral experience - video game pinball can't reproduce it - and stop playing the cerebral game. And it keeps many games shorter than they could be.