Example: There is a hip hop event going on that Tom would like to go to, but he ends up not going “because it’s too cold outside.” In this case, Tom have fallen victim to his circumstance inasmuch as he let it dictate his actions. It’s clear from this example that the cold weather is not at the source of the reason for Tom’s action or inaction. Rather, he would be being more honest and accurate if he said “I didn’t go the event because I chose to use the cold weather as an excuse not to go.” Had Tom actually made the choice to go to the event, the circumstance of the cold weather would have remained the same, but he would have actually done what he wanted to do. Ergo, had Tom chosen to go to the event despite the cold weather, he would have not fallen victim to the circumstance.
Caveat: There are such things as real victims in the world, and therefore it is possible to be a victim to circumstance without choosing it. For example, had Tom been walking down the street and randomly gunned down by a raving lunatic, this would be a circumstance that prevented Tom from getting to the event without his choosing. In essence, a real victim is one who has had their freedom to choose forcefully taken from them.