Coaches talk about it all season long. As do the players. And the media.
Do they talk about it too much? Is it overrated?
Anybody who watched the past two games of the NBA Finals wouldn't ask that question. The Lakers couldn't seem to do anything right in Game 5, nor did they do much if anything wrong in Game 6.
And it was vice-versa for the Celtics.
What exactly is the difference? The court is the same size in both arenas, the basket is the same height and the referees are supposed to make the same calls.
As a former player, I would compare it to driving to work. Because you do so every day from home, you could probably get there with your eyes closed.
If you have to drive to work in another city, you may not know where you are going. So you are paying attention to the map. You are distracted by all sorts of things you don't normally worry about.
Playing at home nullifies so much that can clutter your mind on the road.
The result in Game 6 was a massacre for the Lakers.
It was evident right from the start when Kobe Bryant decided to be the aggressor right out of the gate. He immediately set the tone, realizing that getting others involved early unfortunately doesn't seem to work.
While everybody from one end of the roster to the other contributed for the Lakers, nobody was bigger than Pau Gasol, who was one assist shy of a triple double with 17 points and 13 rebounds to go along with his nine assists. Add to that three blocked shots.
When he has not been able to respond with a big effort, Gasol has been the target of heavy criticism. Being called soft, unfair as that might be, stings. This is a man who takes a lot of pride in his game.
The difference in Game 6 was that Gasol didn't wait for opportunity to come his way as he has done on occasions in the past. He didn't hope the ball would come inside to him. He demanded it.
When Gasol played in Memphis, the Grizzlies brought him the ball. He was the cornerstone on that club. When you are on a team with Kobe Bryant, you've got to demand the ball.
Finally, there were the two benches. There was a huge disparity between the reserves in Boston, where the Celtics' bench stepped up and the Lakers' bench disappeared at times.
In Game 6, when Kendrick Perkins had to be helped off the floor after suffering a sprained right knee, the Celtics needed a boost from Glen "Big Baby" Davis and Rasheed Wallace. What they got instead from the two of them was a combined 0-for-10 from the floor.
Remember the Shrek (Davis) and Donkey (Nate Robinson) Show in Game 4? In Game 6, it was Shrek and Donkey, Act II: Lost in the Woods.
Which brings us to Game 7. It's going to be a long 48 hours for the Celtics as they ponder their collapse.
Ultimately though, Game 7 will come down to a simple question: Who wants to be a champion?