Perms and hair color. You can color hair that has been permed, but try to use a semi-permanent or 'no-ammonia' color instead of a normal permanent color (which uses ammonia and 20 volume peroxide). Have your hair permed first.
Mowing grass works best when the grass is dry, as grass tends to bend over from the weight of the rain, making it difficult to get a straight cut. It also clumps inside your mower cavity and on your lawn, which can lead to dead grass underneath the clumps if not raked promptly.
A: No. If your lawn is doing fine and the soil isn't compacted, there's no need to aerate at all. (Aeration involves using a machine that removes finger-sized cores from the soil and deposits them on the surface to create more air space.). If your soil is compacted (and many are), fall is a great time to aerate -- ideally right after a rain when the soil is soft. Some years other goals take precedence, though.