We should focus on today rather than thinking about future or past because no one knows whether we will be alive tomorrow or not and when we wake up we should first of all thank god for giving us one more day to enjoy the life.
So next time when you wake up in morning simply be thankful to god for the beautiful life as no one knows what will happen next day.
There was a interesting instance happened during Mahabharata when a Brahmin went to talk to yudhiṣṭhira and after reaching the palace he called for him but yudhiṣṭhira was busy in discussing things with other who were already sitting with him so he waited for him for some time and then again he called yudhiṣṭhira to listen to him and yudhiṣṭhira again asked for some more time from him to get free.
After some time again Brahmin asked yudhiṣṭhira whether he was free to talk to him but he was still busy with other people and asked him to wait.
The whole day passed and Brahmin knew that yudhiṣṭhira was very busy and he became sad that he was not able to take out time for him but to thought that he should give it a last try and politely asked yudhiṣṭhira to listen to his problem but unfortunately yudhiṣṭhira was still busy but this time yudhiṣṭhira told him that he will talk to him next day as he was not having any time. Brahmin became sad and started walking towards his home.
When he was on his way Bheema saw him and asked why he was sad so he told everything to him that he wanted to discuss his problem with his brother yudhiṣṭhira but he did not met as he was very busy and asked him to meet next day.
Bheema asked him to wait and asked the drummers to play all drums continuously and keep playing the drums.
Initially no one was much bothered with playing of drums but when they kept on playing the drums yudhiṣṭhira came out and asked what the matter was.
Beehma told him that drum was being played because yudhiṣṭhira has conquered death and knows when he will die so they are celebrating his victory. yudhiṣṭhira was very surprised after hearing this and asked Beehma why he said like that? Bheema replied to him that the Brahmin was waited whole day to discuss his matter with him but he asked him to come next day that means yudhiṣṭhira knew that he will definitely not die another day and was very much sure about it that is why he said so.
yudhiṣṭhira understood his mistake and apologized to Brahmin and listen to hi problem and solved his query.
So the zest of the story is that we do not now when death will come to us so do whatever you want to do today and do not leave things on tomorrow.