In the recent past, I had regrets of not trying what I could do at certain times but didn't because of an unknown fear. As soon as I accomplished to overcome fear, I learnt another thing too, We should not regret on our past from which we have learned at least something. Right or wrong, whatever you did in your past, was for some purpose and this is how life works. Holding regrets for past won't help you in your present and eventually you won't be able to grow. Let the life go and continue to grow. :)
Now, I can proudly say that I fear of not trying and then I take action immediately :)