The two lamest excuses that someone who is supposed to be an adult can give are:
1) Its complicated
2)I'm an adult and I can make my own choices.
Both represent a lack of control on the situation at hand and it proves that adults are just big kids with more problems. And since they don't want to deal with the situation at hand their responses are these lame ones. I mean adults use these excuses all the time when they no longer want to discuss something because they know that there is something that is ridiculous about their thinking. They are so caught up with the teenager syndrome where they cannot have someone else tell them what to do that they will object to just about anything. Its like the case for ethical neutrality where no one else can tell you what to do because only you know what is best for you. It doesnt work. As in True Tolerance it states, "No one is so poor as to lack a richly stocked storehouse of self-deceptions, often transparent to everyone but himself. The alcoholic who insists that he is indifferent to the bottle is merely a conspicuous example of the kind of dishonesty with self we all practice inconspicuously. Moreover, even when we do know what is best for us, we do not always pursue it. This di due only in part to pride and weakness of will. Defects in our institutions can actually make our best courses impossible to follow. Then again, without closing off any course completely, they may yet offer all-but -irresistible temptations to ignore the long-range consequences of wrong or foolish choices."
And I think that perfectly explains #2 so I will leave that one alone.
Now for #1
It's complicated, I mean can it get any lamer. Really well yeah we know it's complicated, but how'd you get there in the first place. Probably through a series of choices from #1 and so since you know you have made a little bit messed up choices due to your own pride getting in the way, well then you have to justify it. And your justification is simply its complicated. Why don't you do something about that, get your head on straight and make better choices. We all can learn from mistakes if we truely let ourselves be repentant.