lead a dog's life

[life] See: [BETWEEN LIFE AND DEATH], [BIG AS LIFE], [CAT HAS NINE LIVES], [CHARMED LIFE], [COME ALIVE OT COME TO LIFE], [FACTS OF LIFE], [FOR DEAR LIFE], [FOR THE LIFE […] A Dictionary of American Idioms

for the life of one

[for the life of one] {adv.}, {informal} No matter how hard you try. - Used for emphasis with negative statements. * /I can't for the life of me remember his […] A Dictionary of American Idioms

life of Riley

[life of Riley] {n. phr.}, {informal} A soft easy life; pleasant or rich way of living. * /He's living the life of Riley. He doesn't have to work anymore./ Compare: […] A Dictionary of American Idioms

school of hard knocks

[school of hard knocks] {n. phr.} Life outside of school or college; life out in the world; the ordinary experience of learning from work and troubles. * /He never went […] A Dictionary of American Idioms