Today is what you have now...Past is what already gone..Dont be a prisoner of past..sticking to the past only gives you mental stress which leads to depression..Forget if you have made mistakes in your past.Mistakes are the part of life..But sticking to them is curse...Think about the lesson you learnt from them and never rpeat the same...Life is a precious gift which is given only one time...Don't waste it thinking about past..The moment which is gone will never come back..Never stress out yourself for the past and future...Live in the moment you have..Forgive yourself and make yourself ready for whats coming in your life..Forgetting past is the only hack to be happy in life..
You can only act in the now. but you can also plan for the future.