To appreciate small or minor benefits, advantages, or opportunities one is afforded, particularly in the midst of an otherwise difficult, frustrating, or unfortunate situation or circumstance. My car's air conditioning stopped working two hours into my cross-country road trip across America. The radio still works, though, so I guess I should be thankful for small mercies. Our son's accident left him without the use of his right eye; we're just thankful for small mercies that he still has the use of his left one.