Today I gave my buddy at the shop a cycling cap that I had bought that just did not fit my head well at all. Of course, it fits him perfectly and is like it was made for him. Cleaned what appeared to be the filthiest drivetrain I have ever seen in my life. Pulled black boogers of greasy gunk from the cog. Chain was an absolute mess. Looks so much better now.

Pro tip: If you use Tri-Flow chain lube, be sure to wipe off the excess. Used it 4 times now and forgot each time. No bueno.