Ayya Khema:

Due to having made karma, rebirth consciousness arises. But we need not think of rebirth only in a future life. We are in actual fact reborn every moment with new thoughts and feelings, and we bring with us the karma that we made in the past moments. If we were angry a moment ago, we are not going to feel good immediately. If we were loving a moment ago, we would be feeling fine now. Thus we live moment to moment with the results of our karma.

Every morning, particularly, can be seen as a rebirth. The day is young, we are full of energy and have a whole day ahead of us. Every moment we get older and tired enough in the evening to fall asleep and die a small death. All we can do then is toss and turn in bed, and our whole mind is dreamy and foggy. Everyday can be regarded as a whole lifespan, since we can only live one day at a time: the past is gone and the future may or may not come; only this rebirth, this day, this moment, is important.