Since at the beginning and end of our lives we are so dependent on other's kindness, how can it be in ......the middle that we would neglect kindness towards others?

Be kind whenever possible. It is always possible.

No matter what activity or practice we are pursuing, there isn't anything that isn't made easier through constant familiarity and training (I think you can apply this to soccer as well)

I am basically optimistic.

I love smiles. That is a fact. How to develop smiles? There are a variety of smiles. Some smiles are sarcastic. Some smiles are artificial-diplomatic smiles. These smiles do not produce satisfaction, but rather fear or suspicion. But a genuine smile gives us hope, freshness. If we want a genuine smile, then first we must produce the basis for a smile to come.

The highest happiness is when one reaches the stage of liberation, at which there is no more suffering.

Spend some amount of time alone everyday.