Which excerpt from The Last Lecture best supports the idea that the process of setting and pursuing goals can be rewarding?

Here is an excerpt which fits that description:

There's a lot of talk these days about giving children self-esteem. It's not something you can give; it's something they have to build. Coach Graham worked in a no-coddling zone. Self-esteem? He knew there was really only one way to teach kids how to develop it: You give them something they can't do, they work hard until they find they can do it, and you just keep repeating the process.

This excerpt is about how the challenge of pursuing goals can help build character. Pausch is against entitlement or people trying to get things the easy way, which he thinks is unhelpful to one's own mental health. By doing something, one gets self-esteem and the confidence to push further in future goals. This cannot be done for an individual nor can nice words make it magically appear. Self-esteem must be, as Pausch puts it, built through deliberate action and persistence even in the face of failure and setbacks.
While the end-goal is good in and of itself, Pausch hammers home the idea that hard work is a good thing in and of itself as well. It makes getting the end-goal all the sweeter, and the experience of reaching the goal helps people go farther with future goals, too.