And he also knows what a coup it would be for Paul O'Connell's side to repeat the stunning series victory of 1997 when the Lions lowered the colours of the then world champions.
So, with the first game of the 2009 tour a mere four days away, Gatland gave his views on how prepared his players are for the challenge ahead at a press briefing in Johannesburg.
"This is almost an impossible challenge. It is vital that we are competitive and that we gel together very quickly," said Gatland.
"We are starting from scratch as a squad and we have to bring pride, passion and desire to everything we do. When I was in South Africa with Wales last summer after our Grand Slam campaign I learned that you have to be very precise and accurate against the Springboks.
"We improved each week on that trip and I've been very impressed at how quickly the players have picked things up in the week we have been together. We are a lot further forward thanI ever expected and that shows the calibre of the players in this Lions party."
This weekend's first assignment against the Royal XV in Phokeng, near Rustenburg, will give Gatland and his fellow coaches a chance to assess the players in the heat of the battle and he can't wait to get them on to the pitch.
"Everyone is very excited at the prospect of pulling on the Lions jersey for the first time, but who wouldn't be? The opening game is important to build confidence," added Gatland.
"We are looking to play a pretty good brand of rugby and I don't think we'll have any problems adapting to the ELV changes. There has been a lack of variation in the game and now it will revert to being more exciting, more fast flowing.
"But I still come back to the main point. To beat the Boks you have to be good at the set-pieces and accurate for the full 80 minutes.
"There is a theory that the Springboks might be a little bit undercooked coming into the series having not played together since November. But I have the ultimate respect for them.
"You can see they have enormous strength in depth from the Super 14 and the guys who pull on that green jersey are always ready to die for the cause. They are tough and physical on the field and really passionate about the game."
In 2005, when he left London Wasps to return to work in New Zealand, Gatland predicted the All Blacks would win the series against the Lions 3-0. They did just that.
Four years on, he feels the Lions are ready to improve dramatically on that disappointing performance.
"The players who were involved in the 2005 tour were very disappointed at the outcome and really want to make amends - especially the captain. Lot's of things have changed since then," added Gatland.
"This tour is based on traditional Lions values and we are looking to gel the whole squad into a tight knit unit. We are looking for a good start this weekend, but everyone realises that it is the Test series that matters above all else.
"Everyone remembers who won the series and, for us, it is a matter of honour."