That task, the one that's been on your to-do list for three months now, maybe even three years, dare I say three decades.
You'd start today if you knew you could do it perfectly and would be received as such.
But you can't, so you won't.
It's safer to do nothing and stay the same than it is to put yourself out there and run the risk of validating what you already believe about yourself.
The attraction to known misery is that it's known, and the aversion to unknown joy is that it's unknown.
Of course, I can tell you that perfection is a mathematical equation, that no one cares as much as you do, or that perfectionism is a form of control, but I'd only be appealing to your rational brain, never so much as scratching the surface of your emotional brain, where the real wound resides.
Until you recognize that you've fundamentally confused some relative experience of rejection from your past for your absolute identity, it's unlikely you'll ever show up, because you've subconsciously placed your worth on the line and there's too much at stake.
However, once you get the joke, once you realize that YES this did happen, but NO it's not who I am, you'll finally get at that task, not because you've suddenly become courageous, but because you finally know who you are apart from your experiences.
And eventually, perfect won't make much sense, and better will become better than perfect.
"Life is the art of drawing without an eraser." John W. Gardener