From my own perspective, the people who look back are people that don't care a lot about the future. They're so thankful for what life has given them but they don't have a lot of hope. They're happy with what they have and everything for them is fine.
The kind of people who look just in to the future, sometimes they're thankful for what they had / have. But they just want more and more. It's a good point you want to be a winner and work for what you want. But sometimes these people don't appreciate what they'd had before.
Finally the third kind of people for me are the people who look back and they're thankful and appreciate everything that happened with them before but at the same time, they look forward. And they look for a better life, a better job or whatever they want to.
These people keep believing in their dreams, making everything possible.
So in this way they can look back and foward and be proud of themselves.
