Past Present Future...

I believe the answer is 20-50-30.
There are three components to our lives : looking at the past and reflecting,executing in the present and living the moment and thinking of the future and planning ahead.
While each component has a key role to play in shaping who we are and who we become as human beings (personally and professionally), I believe there does need to be some sort of a balance between the three elements for optimizing our time on Planet Earth (or Mars, if you Martians are reading this).

That answer I believe is 20-50-30.