The Prophet ﷺ once delivered a speech in front of us wherein he left nothing but mentioned (about) everything that would happen till the Hour. Some of us stored that our minds and some forgot it. (After that speech) I used to see events taking place (which had been referred to in that speech) but I had forgotten them (before their occurrence). Then I would recognize such events as a man recognizes another man who has been absent and then sees and recognizes him.  

لَقَدْ خَطَبَنَا النَّبِيُّ ﷺ خُطْبَةً مَا تَرَكَ فِيهَا شَيْئًا إِلَى قِيَامِ السَّاعَةِ إِلاَّ ذَكَرَهُ عَلِمَهُ مَنْ عَلِمَهُ وَجَهِلَهُ مَنْ جَهِلَهُ إِنْ كُنْتُ لأَرَى الشَّىْءَ قَدْ نَسِيتُ فَأَعْرِفُ مَا يَعْرِفُ الرَّجُلُ إِذَا غَابَ عَنْهُ فَرَآهُ فَعَرَفَهُ