before i even get to asking the question what are the odds, i first ask: is this opponent going to pay me off if i catch? do i even want to consider this play? why?

certainly odds are part of this equation, no doubt. but if you can answer those types of questions (he just paid off a hand the hand before and might be on tilt, he has been complaining of being bullied, is a demonstrably poor player, he'll never pay off my whole stack, etc.) all of a sudden the odds get a lot more relevant. First ask why you should even bother calculating them in the first place.