Trains.

Trains pass us by every second.

Sometimes we run to catch them.
Sometimes we just let them pass.

Some are going so fast we'll fail to catch them if we don't choose them right away.
Others are going faster and we won't see them if we don't keep our eyes wide open.

Those trains are our chances in life,
it's up to us to choose them wisely,
it's up to us to choose them quickly,
it's up to us to keep our eyes open.

Life is up to us.