Atlas,
Watch this YouTube at the 20 minute mark. He talks about how the brain responds to triggers, startles, etc.
P-51 Engine Out, Off-Airport Landing - full analysis - YouTube
The key issue is recognizing the trigger as just a trigger, not a reason to continue in the anxiety/startle reaction.
For you, this means changing your though process to a thought that diminishes the meaning of the movement or bump. If you don't do this, you are setting yourself up for failure.