"It didn't feel difficult at the time because I was so charged up about both books. Afterward, however, I was pretty tired. In a good way, like after a great workout"

This quote by Jonathan Kellerman speaks with the power of enthusiasm and inspiration. When we are enthusiastic about something, it can give us the energy to push through uphill struggles. In this case, Kellerman was so ecstatic about composing 2 books that the task of writing them didn't feel hard. Later, however, he was tired, however in an excellent way, like after an excellent exercise. This recommends that the effort deserved it which he was satisfied with the outcomes. It also implies that when we are passionate about something, it can assist us to press through uphill struggles and accomplish our objectives.