The term used when one feels over it / done with something stupid. If one can't stand what's going on in one's environment, they will say "sobrelo" to show frustration with the ignorance of the situation. Also, the saying shows that that person saying it feels more mature than everything / everyone involved. Literally means, in Spanish, "over it", in a physical sense, though.

When you eat dirt for the first time and leave your family to build a shack in the woods