Let me preface this bit of wisdom with this: I have problems. Mental and physical problems. Just like every human being on Earth. But that's okay. You just have to trudge through it. It's part of life. You deal with it and roll with the punches. After a while you get used to the pain and don't even notice it anymore.
Unless you're talking about ingrown toenails.
I've suffered from ingrown toenails sporadically through out my life. As anyone who has every had said affliction will tell you, this probably has the highest pain-to-severity ratio that there is. Also chewing on tin-foil. But that is neither here nor there.
For as long as I can remember, I've always dealt with my toes in the same manor. During normal foot and toe maintenance (clipping of toenails), I would inevitably cut a toenail too short. Instead of growing out, away from the foot, the toenail would grow back out towards the sides. This would cause the toenail to cut into the edge of my toe.
To deal with this problem, I would use a pair of forceps, a pocket knife, and pair of nail clippers to dig out the portion of nail that was cutting into my toe. This was painful. It would relieve the pressure for a time, but would always get infected, leading to a month or so of this "dig and wait" routine.
One day, it got so bad that I went to the doctor. I was hoping that she would anesthetize the area, and use somewhat sterilized instruments to remove the portion of the nail and perhaps cauterize the cuticle so that the nail doesn't grow back on the edges. Of course, that's not what she did.
She told me, "I can just remove the nail, but it will grow back and probably keep getting ingrown. The only long term solution is to cut a notch in your toenail to relieve the pressure until the corners have a chance to grow out."
In my infinite wisdom I thought this sounded like a load of crap, but I'll try just about anything once. And I did. And it worked.
The notch immediately relieved the pressure. I was able to walk home without the excruciating pain shooting from my toes. It was bliss.
Below, is a crudely drawn diagram made in MSPaint. The blue lines represent the direction of force/pressure. The "BAD" side shows that the pressure goes out and around, causing the nail to dig into the edges. The right or "GOOD" side, show that with the notch, the pressure is directed towards the notch and away from the edges, relieving the discomfort.

To this day, I keep my toenails notched. Just in case. I figure it can't do any harm. Except occasionally I'll scratch up my leg when I'm asleep at night if I don't smooth it out. And sometimes it'll snag my sock. But both are small prices to pay to relieve one physical ailment that literally cripples me from time to time.
I hope this was helpful. Had I known of this remedy 10 years ago, those ten years would have been a lot less painful.
~~Ben
Resources:
Anatomy of a Toe Nail: (http://thefootblog.org/2006/10/20/anatomy-of-a-toe-nail/)
Ingrown Toenails on Wikipedia: (http://en.wikipedia.org/wiki/Ingrown_toenail)
Regular Toenails: (http://en.wikipedia.org/wiki/Toenail)