The ambitious two-week run of “Patti Smith: Dream of Life,” beginning today at Film Forum, banks on the unconventional documentary’s appeal to different audiences. For fans, it’s a righteous, heartfelt trip through the mind of an icon and inspirational force. For the many bystanders who appreciate Ms. Smith’s important place in music history, it’s a ruminative reminder from the woman herself of a larger literary context beyond being a “rock poet.”