Life?

It's not about money,friends or family that make your life appealing,it's about how you feel and the efforts that you had spent and put on.My teacher once told me that don't ever use 'In my Life' this three words in our essay as we are just too young to use it.But I'm totally disagree with what she said because everyone owns their own distinctive life .Even if we have just live on this planet for not so long,we have also past through some moments that not all of the people have experienced before.Am I right???