But the ex-school teacher says his Super Rugby and Tri Nations titles and his record-breaking 11 straight wins with Wales will pale into insignificance if he can guide the All Blacks to global glory next month.
"That's probably right," admitted Henry when asked if 2011 would define his time in professional rugby.
"I think this Rugby World Cup is very defining for this team. This team has done pretty well over the last few years - it's been ranked number one in the world and won a lot of championships.
"But at the end of the day the big one is the Rugby World Cup - everyone knows that and that is going to define this team and the people associated with it."
No Kiwi coach has lifted the World Cup since the very first tournament back in 1987 when the All Blacks triumphed on home soil.
Despite being favourites at almost all of the five competitions that have followed, New Zealand have managed just one more World Cup Final appearance in 1995. Semi-final exits in 1991, 1999 and 2003 were painful enough but a last-eight exit to France under Henry's leadership in Cardiff in 2007 has piled even more pressure on the 65-year-old coach.
And with this year's tournament being played on New Zealand soil, Henry says he is already seeing a see change in mindset ahead of the opening fixture against Tonga this Friday.
"You know the tournament is on. In the south of France we were reasonably isolated from the hype there. In a small country of four and a half million people, it's a playing field where everyone is involved, so it's a different feeling altogether," added Henry.
"The guys are pleased they are here. There's been a lot of talk for a long time about the Rugby World Cup. Our minds were in two places during the Tri-Nations but now we are here, I think they are very pleased about that.
"They are probably a bit quieter, a bit more focused, a bit less banter. So the serious business has started or is starting shortly. They are in good shape."