I believe self-discipline is the key to unlocking life's greatest treasures. I try having self-control when it comes to things like working out, getting in shape is just as much as a mental task as it is physical. Getting myself in and out of bed at a decent time is another good example.
I have a lot of self control. Kicked a drug habit, cold turkey. I've had urges and it's been difficult to say no to but I've controlled myself. Nothing is worth losing everything I've worked so hard to get.