There is no need to bother about the past.
As you become aware, the first thing to disappear from your mind is the past, and the past is one third of the mind. It is the very base of the mind, the foundation. Once it disappears, then the whole building starts collapsing.
The 2nd to go is tomorrow.
When there is no yesterday, you cannot conceive of the tomorrow. The tomorrow is nothing but a projection of yesterday. You would like to live the joys of yesterday again tomorrow and you would like to avoid the miseries of yesterday. That's what your tomorrow is. If yesterday is gone, tomorrow is finished; soon it will disappear.
And when yesterdays are gone and tomorrows are gone, where is today?
It exists between the two. If both the banks have disappeared, the river itself will disappear.
If both the banks have disappeared, the bridge will disappear. Chunk by chunk in three pieces, time dissolves: First the past, then the future, and finally the present. Then you are left with no time, a state of timelessness. And this, Buddha calls nirvana.
To experience timelessness is to experience deathlessness.
To experience timelessness is to experience that which really is. It is neither past nor present nor future; it simply is. It cannot be confined into any compartment, into any category; it cannot be categorized. You simply experience each moment with tremendous peace and silence and joy.
And each moment becomes so fragrant, so alive!
Each moment becomes such a benediction that it is impossible to imagine it, it is impossible to describe it. One has to know it to know it; there is no other way. Nobody can explain it to you. It is not expressible, it is not explainable. It is the greatest mystery.
When time disappears, mind disappears – what is left?
That which is left, that vastness…that's your real being – in Buddha's words, your non-being, your no-self.
(Osho)