For some reason I can vividly remember all of the games I played when I was younger but not games I have played as recently as a couple of years ago.
For example I remember everything about GTA Vice City, but almost nothing about GTAIV missions.
I switched on Super Mario World recently for the first time in years and I remember the stages as if I had only played them a day before. Meanwhile, when I played New Super Mario Bros U recently, which I only completed at the start of this year, it felt like I'd never seen half the stages before.