Direct answer
Objectives follow journal display order. Some depend on your choices; follow the active objective in the game.
Result
Life on the Path is full of surprises. One day, a milkmaid's offering you a warm mug straight from the cow. The next, you're helping drag a merchant's wagon out of the muck. Other times, you witness thugs raiding a house. The last happened to Geralt while he was wondering across Ard Skellig.