I'm sure it's different for everyone. I scratch my head watching her only because I see how all her over-prepping fails her over & over & over. She never allows for the uncontrollable, never expects something unpredictable to happen.... HOWEVER she speaks as though she does. If it actually worked for her, I could see why it would be a hard habit to break.
And that procrastination thing - oh yes. She pushes deadlines past reasonable (despite all the careful attention paid to the plumbing, {eyeroll} then rushes to turn chicken crap into chicken salad (to paraphrase one of RAH's favorite sayings, ha!) & comforts herself later when it wasn't done to her expectations, by reminding herself that she was victimized by the loss of time due to the plumbing repairs. What?
I spent the first 3 yrs learning that if I prepare too early ahead of her "real" timeline, I'll re-do the stuff 3x before we get to the actual moment of necessity. If I let her know that there are 50 different shades of green to choose from for a marketing piece, I'll pull my hair out for 3 days while she decides. If I narrow it down to the top 5 that I KNOW she'll like? She'll find one that she loves inside of 15 minutes. And if later she finds that I eliminated 45? She'll spend time reviewing them all & still settle on the one she originally picked. BTDT, learned that lesson. It's gotten better because she's built trust in my decisions after going through that process so many times, thank god.
For her I know it comes down to vulnerability (I've told her so) and blame. Even when it's not
angry blame, she has to know where to put it. Fault must be assigned before she can move forward (& she'll do so happily in most cases, she's not a purposely negative person). I told her I'm buying her Brene's books for Christmas because she loves that kind of reading to begin with & this is a perfect add-on to her collection.