Remember the worst days He brought you out of.
Rescue from Fir'awn, and the trial within it
Allah reminds the Children of Israel how He saved them from Fir'awn's people, who killed their sons and kept their women alive. Ibn Kathir says Musa reminded them of this to show what Allah had done, and the verse calls it a great trial from your Lord.
You forget the year you could not pay rent, the night in the emergency room, the season of feeling completely alone. Life is easier now and you grumble about small things. Remembering the rescue puts today in its place.
The hard years are behind me, better not to think about them.
Remembering where Allah brought me from keeps me grateful and humble.
Think of one hard time Allah brought you through. Say alhamdulillah for it specifically.