We all want to be good, but we all have moods.
Our biology determines that the chemicals and organic systems inside us have erratic tendencies. We receive stimuli, and we react to them emotionally. We go through developmental stages, and we react to them chemically and therefore emotionally.
So it would be wrong to think of ourselves as blank slates, on which we can impose whatever projects and ethics we like, without taking into account our animal nature.
However, there is nothing wrong with aspiring to achieve a good attitude with the mind that we have, even if it is often distracted.
Many buddhist philosophers hold that our essential mind is free of prejudice, and is actually quite calm and naturally reasonable and compassionate. This may be hard for some to believe, since it seems so evident that our animal selves are flooded with less reasonable and compassionate tendencies.
Even if we do not believe in the essential goodness of our minds, we can take some optimism from some philosophers, such as the Dalai Llama, who hold that, as we are social beings, our biological selves have at least some tendency towards kindness and generosity.
There is no doubt that humans experience variations in mood. It can be easy to meditate one day. Then, apparently for no reason, we can become disturbed, and find it almost impossible to meditate peacefully the following day.
How you manage your moods may depend on your view of the human condition.
Have a think about your own view of the human condition.
Do you believe that humans are essentially bad, and need training into good habits?
Do you believe that we are all a mixture of good and bad traits, and that we can develop some of the good and lose some of the bad?
Do you believe that humans have an essentially good mind, and that we can become enlightened by attuning to it?
Humans are animals, and subject to moods which distract us from good behaviour.
Even so, we are social animals, and we have elements of natural compassion to build on in our relationships with others.
Some people even believe that we have an essential potential for good, if we can only attune to it and lose our delusions.
In terms of making the most of our development, and our meditation, we can choose to be generous towards others, and challenge ourselves to improve. That attitude may give us the best chance of a happy life.