When a person gets injured by spraining their ankle, hurting their back or whatever it may be, one of the most common mistakes made is that they do not completely rehabilitate their injury. People do it for a variety of reason: laziness, overconfidence in their ability to heal, ignorance to the severity of the injury, etc. This is a terrible mistake to make because if you do not completely rehab, this injury can linger and cause much more pain and frustration than it should have.
I had a friend who sprained his ankle playing basketball one night and he did not ice it or anything because in the past his ankles had always healed themselves. He kept waiting and waiting for the swelling to subside, but it did not for the longest time. So, he became impatient and instead of going to see a doctor or specialist, he figured he would play through it. As he was playing, since the ankle had never been given time to repair itself due to the swollenness and lack of care, he resprained the ankle. After the resprain, my friend decided to see sports therapist and was told it would take roughly three months to heal, as opposed to two weeks if he had taken care of it the first time.