When somebody is sad, you suddenly think of something to make him or her happy but unfortunately you don’t do it. Later you realise that you should have done it, but now it’s too late because you have forgotten that something!!!!
In the very similar way sometimes we plan many things to achieve our dream, we dream about our dream, we think how we can be the best in the dream but unfortunately rather than accomplishing the dream, we continue dreaming. Later when we wake up, we realise that we should have done what we dreamt, but now it’s too late because we have forgotten the dream!!!!!