'Sometimes your best isn't good enough'

Once again, this is something from music. I think music is a really good way to get an idea through, but anyway...
this is the title of a song by the churchills. As i was listening, i was thinking to myself, "this is so true, it happens to me all the time." I hate the fact that this line is true, because when you try as hard as you possibly can, and you still dont suceed in it, then it make you feel like a failure. thats what i think anyway. A huge part of my life that i am reffering to for this line has to do with school and tests. Sometimes when I have tests, i study day and night every break that i have, i do as much as i can, but i still end up doing not so well. It brings me down because it makes me feel like i cant accomplish things when i want. this feeling makes me really annoyed, but i cant really do anything. "Sometimes my best just isn't good enough."