Bingo. We've made it too easy in modern society to meet basic needs. I look at all the obscenely obese people in the USA and wonder how they could NOT be depressed. Millions of years of evolution brought us to a point not all that long ago where life was dominated by work that was required to survive, and only the fit survived. When I was younger and always training for the next marathon, I often got a deja-vu type experience on long runs, a little voice that would say this is what God or nature really intended for you to be doing---running, walking, hunting, gathering, struggling to make it to the next watering hole. Didn't need prozac in those days as the brain was swimming in a bath of good chemicals.
On a related note, I like the opening salvo of Scott Peck's The Road Less Traveled that I paraphrase: Life is difficult. The more we accept that, the easier it's going to be.
Yes, this is not heaven - this is earth. Yet, we expect it to be heaven. Earth is filled with life, love, death, accidents, sorrows, crying, laughing - all of it - good and bad.