Usually that phrase is reserved for brains, but in today's post I will show you it's also true for nail polish coats :p
I think most people will agree that more often than not two or more coats of polish are required to get full coverage of color. Or perhaps the formula is streaky and requires a few extra coats to even it all out. However, I find there is one other advantage of doing two coats.
First, please excuse the dry fingers in the pictures. As part of my mani prep I use acetone to remove old polish and oils and only moisturize after the mani is done since a clean, oil free nail surface is required to make mani's last.
Not too bad, but it could be better since I like to criticize myself.
This picture is with two coats. The coverage near the cuticle is much more even and now moisturized :D
Moral of the story ... why do we do two coats even with opaque polishes ... because it's a habit AND because it looks prettier!