I used to say, whatever has happened has happened. It is silly to resist this. It is silly to get angry or feel sad for what has happened, as it has already happened and there is no way you can do anything about it. The best thing to at this point is to accept this and move on.
A master corrected me. He said such an explanation for acceptance is at a lower level of consciousness as it is tained a bit by ego. He went on that true acceptance is totally, unconditionally, trusting that the divine will knows what is best for one and does everything in out best interest. And, we really do not know what is good for us. We should of course, plan to our best knowledge and do things but the results of the actions is a function of what we do and the divine will. We should accept that what we do is so insignificant in front of the divine will and hence we should totally accept with glee whatever happens!
In this light, my original explanation for acceptance could be read as, 'well, something bad has happened. What can be done? Take it on your chin and move on.' This, according to the master, is tainted by ego as we seem to deny that everything that happens is divine will and by rejecting what has happened we seem to say we know what is better for us, more than the lord. True acceptance is letting go of oneself and saying that the divine will is taking care of me.
Though I have a few uncomfortable feelings in me about this, I can sense how profound this is. I spent about 3 hours one night pondering on this and why it is so difficult for me let go of the mental image of myself. I still have no clue!