There are times when we ought to jump into things and immediately get used to it, but there are also times when we ought to just get used to things little by little. In training for a longer distance race, or recovering from an injury, it's important that we take things slowly and adjust to what we're getting into. The same can go for getting into a new job. At times, it might be okay to just jump right in, but at the same time, it's better for you and less stressful for you if you just take things in little by little and understand the job bit by bit.
Now that I've pretty much recovered from my little injury, I've taken off the tape that was around the bottom part of my knee. With the tape, I ran 8 miles at a decent pace (yesterday) and could've kept on going. However, without it, I don't know what I can handle. Tomorrow, when I go for a run, I'm going to start out real slow because I need to make sure that it's actually healed. If it isn't healed, that means that I'm going to have to stop earlier before I hurt myself by overexerting myself. It also means that I would have to wrap some tape around my leg again to make sure that the muscle doesn't pull away from the bone.
If you really want to be successful and achieve whatever goal you set for yourself, that means that you're going to have to take care of yourself. If you're going to have to take care of yourself, that means that you would test the waters first before you get into it.