If you have a save before you picked any Moments, then you're good to go. But you don't have a save, then i hope this helps. If your mouse has a scroll wheel, i think you can move it up as a way to go back until you reach the Moments Selection page.
Here is the mouse controls guide in the game.
There are also controls of the keyboard (Page Up and Page Down) but for some reason, they don't work for me.