Scientifically speaking, resonance is defined by the World English Dictionary (see dictionary.com) as:
The condition of a body or system when it is subjected to a periodic disturbance of the same frequency as the natural frequency of the body or system. At this frequency the system displays an enhanced oscillation or vibration.In human terms, we all have a core identity complete with beliefs and motivations central to said identity. I came to realize that the things that resonate with us are the things that touch on some part of what we already hold to.
On a superficial level, consider that the reason I found Jericho, the TV series about a post-apocalyptic America, so intriguing is because it mirrors the fall of the Nephite civilization in the Book of Mormon on certain levels and also reflects parts of my personal expectations of the state of the nation in general prior to the Savior's second coming. Someone who does not anticipate (in the literal definition of expecting something will be rather than necessarily 'hoping' for it to be) the same things will not find the same resonating effect.
Or consider King Uther from the BBC Merlin (strong competition for my new favorite series). When he came to Camelot, he was witness to and champion against the extreme misuses of magic in the kingdom. His reign was built upon correcting a gross imbalance of power. Then, when his wife (this version strays on a number of points from the original Mabinogion, and even later Le'morte d'Arthur) died at childbirth from a backlash of magic, his honest distrust and natural antagonism were magnified into outright hatred and brutality. Rather than being able to recognize that not all those who practiced magic did so to the detriment of others, he could only see those who used it for wickedness and therefore condemned everyone.
I have seen it at work on many levels in my own life. For one example, my natural desire to travel, my innate wanderlust, has been augmented by experiences of the inconstancy of my particular family and certain 'friends' which emphasized in my own mind the value of moving on and leaving the negative behind. New starts and change feel like fresh air to me rather than the hated terror of change that others seem to perceive.
I can hear someone asking, "This is all very interesting, but what value does it give?" Consider the wisdom of the ages (attributed to multiple cultures and individuals) to 'Know Thyself'. The more a person can recognize the truth of who and what and why they are, the more control they have over their actions and lives. A person who has an intrinsic understanding of what makes them tick is far less vulnerable to the machinations and manipulations of others, be they man or 'demon' (for those readers of the Christian variety). It gives the person a much stronger foundation upon which to stand lending towards a greater confidence in self and life. And should an honest survey of self turn up something unpleasant, that person then has the wherewithal to make adjustments and counter the negatives found. It is a process that has helped preserve my sanity coming from an abusive home and one I recommend my readers seriously consider employing in their own lives.