This question has subtle implications that can damage a developing personality. So update your self-definition. Learn your whole reason for living and live it fully. If it doesn't, then there's no reason not to waste time, because nothing really matters anyway. You'll want to understand every aspect of life, to do the most with the limited time you have.
Jewish consciousness says that the worst crime is murder.
The worst murder is premeditated. Human beings were created for pleasure. Adam and Eve were placed in the Garden of Eden. Along the way, you'll make distinctions between pleasure and comfort, between necessary pain and needless suffering. And through the process, you'll discover the true meaning of life.