Dogs are Like Piggy Banks

Each reinforcement builds our behavior bank, and asking for that behavior under various circumstances can either add to our bank, or deplete it. If my dog gets in the car to go for a hike each day, they will begin to learn the car predicts a hike and so have a positive association with the car. If I take them to the vet instead, the residual negative association with the car will likely be much stronger, and so take many many more days of associating the car with a hike to undo.