I use to practice karate and my sensei honed in on the importance of stretching.. all that went out myear as soon as I finished. Now I am really appreciating the importance of it. Improved flexibility and less soreness allows me to train harder the next day, and that's why I do it. My schedule doesn't allow me to slack and take too many days off just because I'm a bit sore.
Those who mentioned the foam roller - it is so painful, especially on the sides of your legs, but doing it consistently and often makes it more manageable.. I grit my teeth and force it to roll on the toughest parts.. no pain no gain, lol