Ok, it's a new truck, so you're still getting used to it, but The chime should have been the alerting factor that the engine was left on. This may be a concern that it didnt register.
Last year my 35 year old next door neighbor had a similar thing happen. He drove in his garage, parked, and went inside. 10 minutes later the house alarm went off and a firetruck came roaring down the street.
He had left the car running and went inside the house, and the garage smoke detector went off signaling the house alarm. He didnt smell the exhaust at all. His wife arrived with their kids after the fire truck pulled up and was shocked that the house reeked of exhaust and he just sat watching TV. Totally unaware.
Turns out earlier that week his wife found his car keys in the refrigerator. He tried to downplay it, saying he was probably just preoccupied, but agreed at my wife's urging (she's a nurse) to get checked. Long story short, it turns out that he had a micro-bleed in his brain that somehow affected his cognitive abilities. He got checked out by a neurologist, and in a few week's time had made a full recovery. It was sort like of a stroke, but not quite.
I mention that because at our age, even though we're not old, we have to be open to the idea that sometimes things happen that may point to something else. If it's nothing, fine, but if you notice other things in your life being "different" or being misplaced or lost, keep an open mind and get it checked.