From "Aspiration and Expectation" in Charlotte Joko Beck's Everyday Zen:
If we try to make ourselves calm and wise and wonderfully enlightened through Zen practice, we're not going to understand. Each moment, just as it is, is the sudden manifestation of absolute truth. And if we practice with the aspiration just to be the present moment, our lives will gradually transform and grow wonderfully. At various times we'll have sudden insights; but what's most important is just to practice moment by moment by moment with deep aspiration.
When we are willing just to be here, exactly as we are, life is always OK: feeling good is OK, feeling bad is OK; if things go well it's OK, if things go badly it's OK. The emotional upsets we experience are problems because we don't want things to be the way they are. We all have expectations, but as practice develops those expectations gradually shrivel up and, like a withered leaf, just blow away. More and more we are left with what is right here, right now. This may seem frightening, because our expecting mind wants life to turn out a certain way: we want to feel good, we don't want to be confused, we don't want to get upset—each of us has our own list.
But when you're tired after work, that's the tired Buddha; when your legs hurt during zazen, that's the hurting Buddha; when you're disappointed with some aspect of yourself, that's the disappointed Buddha. That's it!
When we have aspiration we look at things in a completely different way than we do when we have expectation. We have the courage to stay in this moment since, in fact, this moment is all we ever have. If the mind wanders off into expectations, having aspiration means gently returning it to the present moment. The mind will wander off all the time, and when it does, simply return to the moment without worrying or getting excited. Samadhi, centeredness, and wholeness will develop naturally and inevitably from this kind of pratcice, and aspiration itself will grow deeper and clearer.