I'm certainly no PR expert, but here's something which helped me a lot with focussing on the PR process. I decided to focus on experiencing the entire process, immersing myself completely in the experience. So while I keep my purpose in mind whilst turning pages, I also make sure I'm physically and emotionally open to the possible experiences. It helps me to keep focussed on the process, certainly, because it becomes a lot more interesting! Sometimes, the "Why am I doing this?" still comes up, but far less often than it used to, and I'm much more able to deal with it.
Hope this helps.
KWLee