Life is short. A hundred years sounds mammothian. It swells in your mouth and tumbles heavily off the tongue. A hundred years. It deceives us, life is short. Life is too short to accept sadness. To resign yourself to misery. Sometimes these things happen to us, and that is alright, but to choose to cloak ourselves with chain-mail before swimming in the lake at twilight... well. Life is short.
Life is too short to hate your job, you only get one shot at this experience of the universe (even if you believe in reincarnation you will never be this person again). Life is too short to accept friends, lovers or family who damage you, in any manner. You may not think very highly of yourself but you are all you have and it's okay to protect your most valuable asset: your life.
Life is not long enough to let people abuse your trust, lie, cheat or steal from you. It is not long enough to feel guilty when you do something wrong, but there is plenty of time to take a moment to consider all the things you did right today. There is time for thinking, for feeling and for trying new things. There is still time. There is still opportunities waiting to be clawed out of the earth, uncovered and admired, if you choose to go digging.
There will always be time for change, for hope, for love. Until there is not any more time left. So with the time you have left, with the life you have left, there isn't time to accept pain as your lot. If you don't know what will make you happy; try everything. If you do, try that. If it seems impossible to achieve happiness then you must be far away from it so it is time to start walking today, because after all, life is short.