Hoses are a trigger for Jim's PTSD.
Post-traumatic stress disorder triggers are things that can be sensed or thought which remind one of a horrible experience or experiences and give a vibe of them happening all over again.
Things that can be sensed include sight, sounds, smells, touch, or feels.
In this case, Jim reached for the garden hose and grabbed a snake instead. Thus, each time the thought, sound, sight, etc of hoses come around, his PTSD is triggered.
More on PTSD triggers can be found here: https://brainly.com/question/14226334
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