milestone in life

(important) milestone in (one's) life

An exceptionally momentous, significant, or impactful moment, situation, or event in one's life. There is no milestone in your life that will ever compare with the birth of your child. I knew even then that that conversation would prove to an important milestone in my life.
See also: life, milestone
Farlex Dictionary of Idioms.

milestone in someone's life

 and important milestone in someone's life
a very important event or point in one's life. (From the [former] stone markers at the side of a road showing the distance to or from a place.) Joan's wedding was a milestone in her mother's life. The birth of a child is a milestone in every parent's life.
See also: life, milestone
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • (important) milestone in (one's) life
  • important
  • milestone
  • life
  • look on the sunny side (of life/things)
  • sunny
  • the light of (one's) life
  • the light of somebody's life
  • the light of your life
  • mix business with pleasure