Every time I pull out a piece of music I learned in undergrad, I cry a little inside.
"What the !@#$ was I thinking?!?"
Most of the time, in reference to the nonsensical fingerings I chose.
But the same thing happens with most work I did in the past. Even just a few months ago. Sometimes, even a day ago.
Blog posts that don't read the way I write now.
Webpages that I thought were brilliant that now seem...eh...
And even old emails I never deleted from my sent box that were way too long. (Hence, probably never read...)
In the bigger picture, even old laws, statutes, and policies fall into the "What were we thinking?" category.
That's why everything needs review and refining. Not only to appreciate how far you've come, but to keep from making the same silly mistakes.
Either that, or go through the motions and just hope you're heading in the right direction.