As a life mentor, one always needs to tell stories.
Not just stories, but motivational tales.
People of the 21st century have long been immune to motivational 'chicken soup,' but for those in the 1940s, such words were very effective.
Don't be fooled Truman, from high school student to failed businessman to politician, is definitely the protagonist of a motivational story. But even the most inspirational figures have moments of confusion, and that's when a spiritual mentor steps in to offer guidance.
In this respect, Pierre was undoubtedly qualified not for any other reason than his knowledge of history and having read countless motivational tales.
Any one of those motivational stories, if brought into this era, would be considered a delicacy.
After a round of motivational storytelling, Truman was no longer confused; he found his purpose in life and became more confident. Of course, his friendship with Pierre also grew deeper.