'The more things change, the more they stay the same' - I'm not sure who's the first person who said that; but it's a sentence that somewhat explains our tragic flaw; our inability (or fear) to change.
The more you get to know people you realise its kind of everyone's flaw; staying exactly the same, for as long as possible. Standing perfectly still feels better, safer somehow; and if you're suffering at least the pain is familiar. Because if you took that leap of faith, went outside the box, did something unexpected, who knows what other pain might be waiting out there; chances are it could be even worse.
So you maintain the status-quo - you choose the road already travelled, and it doesn't seem that bad; not as far as flaws go... you're not a hopeless addict, you're not killing anyone - except maybe yourself a little, bit by tiny bit.
When you finally do change, it doesn't happen as an earthquake or massive explosion, nor are you all of a sudden this totally different person; it's smaller than that. It's the kind of thing most people won't even notice; unless they looked really, really close - which, thank GOD, they hardly ever do! But you notice it, inside you, that change feels like a world of difference (and you hope that it is); that this is the person you get to be forever, that you never have to change again...