Regret vs Gratitude

If regret wins, pessimism will take over your thought.
If gratitude wins, ambitions will control your mind.

I wish to have no regret in my life.
Even I made my own quote,
"Have no regret" and commit to it.
But regrets come so often when I come to think about it.
Regrets for not being serious.
Regrets for not being ambitious.
Regrets for not being consistent.
Regrets for not being persistent.
So many chances I've missed,so many regrets I've got.
Here and now, what else can be done?
No, sorry, once again, that's a regretful statement.
The question should be
What more should I do?

And the only reason not to have any regrets is
that all we've got in life is His gift.
Thank Him.