I pride myself (against my better judgement) for being able to find argument with just about anything - like finding that one exception to the rule or that particular ambiguous word that leaves wiggle room for interpretation. Sometimes this backfires and I don't understand simple instructions because I see only the problems and not what's trying to be said. Nevertheless, I always attempt to poke holes in a theory before I try to defend it, because it's a lot easier to defend something if you know where it's vulnerable.
The difficulty with this is that it's a lot easier to tear something down than to build something up.
For example, I've discovered a paradox. Nobody I know (including me) holds an opinion without believing it, yet I know that just by merit of being human, I must be mistaken in some of my beliefs, regardless of how well I can argue them. I may be more certain of myself in some things than in other things, but there are people who would contradict me and be just as sure about it. So basically, I can think that I'm right even while I know I'm not.
Not in a specific instance, of course, but generally speaking. I can know that I'm not always right, but I can't know when I'm not right. Even the reasoning I used to arrive at this conclusion throws itself into uncertainty. Another paradox.
This could turn into infinite regression very quickly.
“The point of philosophy is to start with something so simple as not to seem worth stating, and to end with something so paradoxical that no one will believe it.” Bertrand Russell