For better or worse, fate (some choose to call it destiny) plays an important, though often overlooked, role in the life of an adventurer. Sometimes, even the most innocuous events (and an adventurer's choices regarding them) can help to shape destiny by ever-so-slightly guiding the hand of fate.
At various times in your adventures you may encounter the following message:
Suddenly...a strange feeling comes over you... Inexplicably, you feel as if in some small way your destiny is directly linked to the choice you are about to make. It is a fleeting and somewhat unsettling sensation, but it swiftly passes before you can give it a second thought.
The above message indicates a marked choice -- it's a choice that your character is about to make that will in some way somehow affect him or her at some point in the future.
It should be noted when making these marked choices that there are not any correct or incorrect selections. Each marked choice your character makes will have an effect on his or her fate somewhere along the line.
The selections you make when faced with marked choices won't negatively affect your character in any way, though your selections are likely to impact your character moving forward, often in unexpected ways.
Currently, the impact of Hand of Fate decisions on gameplay have yet to be determined. Sometimes they have had slight narrative consequences, like your actions in a quest being mentioned on the text for another one (The Shattered Skull), but they have never been found to affect you directly in the way of gains/loses of XP, Items, access to quests, or anything else.
In short, this is a (yet) unimplemented or limitedly-implemented game mechanic. Don't worry.