It's been three years, two months, & 15 days since my last haircut. Since then I've saved at least $150! It's a pleasure to have longer hair than all the females in your household (and most of the neighborhood). Spouse definitely enjoys my "new" look. You are also treated much differently than a typical short-haired adult-- George Carlin instead of George Bush. People will be more likely to perceive you as an open-minded risk-taker. (TH, I have a great idea for funding a new study!)
Regardless of the hair-care overhead, I think a ponytail is a great metaphor for ER's lifestyle changes. Every day your hair is longer than it's ever been and you're doing something that you've never done before. So the following could be thought of as "downside" or as just a new set of challenges.
There's this awkward stage between "I think I'll grow my hair out" and "There, it all fits in the elastic band" that lasts for about two years. In the meantime you'll resemble Christopher Lloyd in "Back to the Future." (Your growth rate may vary. Measure the distance between your forehead hairline & over the top to the nape of your neck and divide by 4-6" per year for your estimate.) In the meantime you're smoothing it down on the top and tucking the sides in behind your ears about every 10 minutes.
Guys shed more hair than women but you don't realize it until you grow a ponytail. Then you're sweeping hairballs off the floor a couple times a week & untangling long strands from the vacuum's roller brush. Every sink drain needs clearing out twice a year.
Even if you towel your hair dry after washing, it takes 10-30 minutes to stop dripping on your shirt. You may find that one towel only has enough capacity to dry your hair or your body (but not both).
Ballcaps, hats, & helmets will fit differently (or not at all).
Vigorous athletics (like martial arts) will probably require a braid. To preserve your self respect, learn how to do this without asking your spouse for help. Your kids may enjoy helping (unless you ever yelled at them about getting a haircut).
If your hair is curly you'll have an overall frizz that looks like a halo at first and then just looks frizzy. Even if your hair is straight, a typical guy's comb just won't go through the rat's nest. Buy something bigger, tougher, and with at least 1/8" spacing. It's worth using a shampoo with (*choke*) conditioner.
A small elastic band (that doubles over once) is good for regular daily use. Swimming or surfing is better with a big elastic band (that doubles 4-5x). I prefer the "Goody" brand but you have to buy them from the girly haircare section of the store...
I hate shaving. It makes no sense to me that the first thing you do when you wake up in the morning-- bleary-eyed, dehydrated, & uncoordinated-- is put a razor blade against your neck and stroke back & forth many times.
I used to wear a beard on submarines where it was cold & damp (the submarines, usually not the beard). I was not happy when I found out that beards in Hawaii are hot and the breeze blows through them.
ER renders a watch mostly irrelevant but a calendar is essential (to avoid going shopping on weekends). So I use shaving as a calendar-- I try to shave every Monday & Thursday whether I need to or not. That gives me a pretty calibrated chance to get the day by the second guess.
For other ER personal-care issues, read Paul Terhorst on
bodywork.