This is an excellent lesson for students in all grades, however, for the most impact I recommend 3rd grade and up. We went over this in a parenting class I recently took and was surprised that it is relevant even for adults. Students can fill in the outer circle with examples of things we cannot control and the inner circle with the two things they can control: their own ACTIONS and ATTITUDE. You can also come up with a list of things they can and cannot control and ask them out loud and have them decide to test for comprehension. You can give students 2 copies, one to keep and post somewhere and one to turn in or hang in the classroom. I am currently using this lesson in my college & career readiness program for our "Finding Your Passion" component.
There is an entire lesson pack available, as well.