I can lay a field of shingles clean and straight all day long. But the second the roof gets complicated, valleys, dormers, all that flashing around the chimney, I slow way down and start second-guessing every cut. The tricky details are where I still feel like I'm faking it.
More people experience this than they realize.
You can lay basic shingles but complex roofs and flashing details still elude you.
If this sounds familiar, the Library can help you find the bigger picture.