Backpacker:
And I'll probably miss a cockpit filled with electric thingies that show you where you are or shows others who you are, or go beep at various times. And I imagine the checklist in a glider in general is a tad shorter than in a powered plane.
For all practical purposes until you set off cross country you have only three instruments:
ASI - no use on aerotow because you're going where the tug goes. Rather important when winching. Needed on approach. The rest of the time don't look at it.
Altimeter - needed to know when your aerotow is over, and to work out whether you can get back to the airfield, and if your site is near airspace. Not needed for flying circuits (if you start using it, the instructor will cover it up).
Variometer - just listen, don't look at the stupid needle.
99% of the time lookout and fly what you see. You'll learn far faster as well.