Athletes and coaches do not live in in the past, but it can be a source of enlightenment.
The Green Bay Packers and New York Giants have good memories from recent post-seasons. Green Bay went from sixth-seeded NFC wild card to Super Bowl champions a year ago. New York took a similar path to win the 2007 NFL championship - winning at Lambeau Field on the way.
They meet Sunday night in the final game of the divisional round.
In going 15-1, including winning all eight home games, the Packers established themselves as the NFL's elite. They used the bye week to get healthy, and they recall that they defeated the Giants 38-35 on the road on December 4.
Most significantly, they discovered how to win in last year's surge to the title.
"I think we learnt a lot last year being a six seed and having to go on the road," said Aaron Rodgers, the quarterback. "You take on a different attitude as a team as the road team going into a hostile environment. I think that prepares us for the mindset that the opposing team is going to have.
"It is a different feeling, and last year we just got in and this year we had a run and got a bye. So it is a different feeling, but last year really helped."
In 2007, the Giants lost 38-35 to New England as the Patriots completed the first 16-0 regular season. But the Giants gained so much confidence from the narrow defeat that they were not intimidated when they met the Patriots five weeks later in the Super Bowl.
The Giants won 17-14.
The defeat to the Packers last month also brought confidence.
The Giants fell to 6-6 with that fourth straight loss, but won three of their last four to take the NFC East title, then routed Atlanta 24-2 in the wild-card round last Sunday to improve to 10-7 this season.
"We're extremely excited to have all of our key guys intact that we're going to ride with going through this post-season," said Antrel Rolle, the safety, noting that the defensive stalwarts Osi Umenyiora and Michael Boley did not play against Green Bay the first time but will Sunday.
"We're excited. We're excited about the opportunity that's ahead of us and we're excited about playing together and understanding the defence, understanding each other, understanding that this guy is going to be next to us and he's fighting with everything he has."
No visitor has won at Lambeau Field since Miami accomplished it on October 17, 2010. The Giants were routed 45-17 at Lambeau in Game 15 of that season when they were in position to make the play-offs.
Mike McCarthy, the Packers coach, does not expect an easy time against the Giants.
"They are playing well and they wouldn't be here if they were not, so to me, that is to be expected. I think they are playing better than when they played us and earlier in the season they had some tough defeats also. It is play-off football and they are a very good football team."
Before the Giants and Packers renew their rivalry, the Houston Texans (11-6) will be at the Baltimore Ravens (12-4).
Baltimore have been very good in each of John Harbaugh's four seasons as coach, but this is the first time the Ravens are playing a post-season home game after three successive wild-card appearances. The Ravens were 8-0 at home, including a 29-14 victory over Houston in October.
Ray Lewis, the veteran linebacker for the Ravens, said home field is a big advantage. "I don't care who you are, I don't care how good you are, it's hard to win on the road," he said. "For us to work as hard as we did, get 12 wins, do the things we were supposed to do, and now get this home play-off game, we have positioned ourselves to be in the right place. Now we have to go finish it."
Houston are 0-5 in meetings with Baltimore, but their first post-season game, in their 10th season as a franchise, was a 31-10 victory over Cincinnati last Saturday.
The Texans will need a solid performance from the rookie quarterback TJ Yates, who took over for the injured veteran Matt Schaub.