Do not dwell in the past, do ...

Do not dwell in the past, do not dream of the future, concentrate the mind on the present moment.
Do not dwell in the past, do not dream of the future, concentrate the mind on the present moment.

More phrases

If one does not know to which port one is sailing, no wind is favorable.
What a distressing contrast there is between the radiant intelligence of the child and the feeble mentality of the average adult.
We are masters of the unsaid words, but slaves of those we let slip out.
I have always found that mercy bears richer fruits than strict justice.
A lie gets halfway around the world before the truth has a chance to get its pants on.

Quotes from the same author

The only real failure in life is not to be true to the best one knows.
You, yourself, as much as anybody in the entire universe, deserve your love and affection.
A jug fills drop by drop.
Your body is precious. It is our vehicle for awakening. Treat it with care.
Better than a thousand hollow words, is one word that brings peace.