Distinction between "boredom and INTEREST" and psychological value is in question now though.

One could ask what is the psychological reason for your interest?
Did boredom lead you to read a book about said subject, which in turn picked your curiosity?

I believe there must ALWAYS be an initiator for any motivation, a psychological/biological reasoning of one or more elements that make people think the way they do. The same could be said about what we like and what we see as being attractive, as being a turn on, as being a positive trait that we look for in other people...

Emotions like 'interest' all come from the eyes of the beholder, and thus may relate to any number of factors that could be known or even subliminal. Either way, I believe there is a reasoning behind every action, knowingly or unknowingly.

I'm up to 4 cents.