Based on modern beliefs, a large part of a firefighter's duty is to rescue cats out of trees. For some reason they can climb them with absolute ease but then they get stuck.
Cat claws only work one way. Their retractable claws are curved and are great for climbing up. To get back down, they would need to climb backwards, which just isn't in their nature. It is something that needs to be learned.
Some cats might just figure it out on their own whereas other might grow dependent on firefighters.