“I'm getting too old for that,” Hem said.

"And I'm afraid I'm not interested in getting lost

and making a fool of myself. Are you?”

With that, Haw's fear of failing returned and

his hope of finding New Cheese faded.

We usually find many execuses for not changing. Such as, I'm too old to do something, I'm afraid I can't do that,  Someone other will laugh at me when I failed, and so on. So, most of us will not leave from comfortable zone at the first time. But mice are different, they do things by intuition.  They can adapt changes quickly.