The megillah (4:1) tells us that Mordechai knew what had happened and he therefore put on sackcloth and ashes and went crying through the streets.
What did Mordechai know that no one else knew? The end of the previous chapter in the megillah says that messengers went out to the entire kingdom with the decree to carry out Haman’s plot, and the city of Shushan was in a state of confusion. Everyone knew what was going on!
Amazing Sefas Emes: Mordechai knew that in shamayim the refuah for this decree was already in place. There was no chance of it becoming a reality! Nonetheless, he went out to the streets mourning and crying to arouse people to teshuvah and be mishtatef in their pain.
It’s davka because tzadikim will cry out to Hashem anyway that they are privileged to be privy to Hashem’s plan and can see the yeshu'ah even before it happens. If you are I knew that things would work out for the best, we wouldn’t be motivated to do daven and teshuvah. Therefore, Hashem conceals from us what the future holds. We see only the bleak reality of the here and now, and must daven and trust that it will get better.