What you think it is: the opposite of "life's a journey not a destination". Best used to describe a way of life or a certain mindset that overly ambitious people tend to have. It basically means valuing the achievement more than the experience!
A: Wow Mark and your dad are like polar opposites aren't they?
B: Yeah I know what you mean Mark's a huge slacker and my dad is completely "life's a destination not a journey".