David Shearer will make mistakes. He will make wrong calls. He will say things he will regret.
He will do so because being Leader of the Opposition is probably the most pressured, most frustrating and, for some incumbents, ultimately the most unrewarding job in politics.
It is all no responsibility and no power. Ask Phil Goff.
That the Labour caucus has catapulted someone with limited parliamentary experience from the obscurity of the backbenches into the leader's office speaks volumes about Labour's talent pool.
The last time that happened the party was also adrift and directionless. Even so, it took David Lange the best part of five years to become leader. Shearer has got there in 30 months.
He has done so because Labour needed to make a clean break with its recent past. His rival for the party's top job, David Cunliffe, could not offer the vital ingredient that Shearer could - an absence of political baggage.
But Shearer also had an X-factor combination of other characteristics - a relaxed manner, approachability and modesty which match those of someone Labour prefers to demonise.
Like John Key, Shearer is a highly marketable political commodity. This means he will get a political honeymoon that Cunliffe would not have had.
But Shearer's easy-going nature disguises what will be a tough-minded approach to rectifying Labour's deep-seated problems.
At his first press conference as leader, he made nonsense of the notion that he lacks polished communication skills by giving an authoritative, unambivalent dissertation on Labour's need to not only reconnect with middle New Zealand, but make Labour relevant to those people's lives.
He said more about that in 12 minutes than Labour has said in the past 12 months. Suddenly the fog around Labour is lifting.
Shearer will bring change by making the party less hostage to the political correctness that still plagues its image. He is interested in things that work, rather than whether they fit the party's doctrine. Shearer will not fight old battles merely to make the party feel good about itself.
He will make the party's various groups - union affiliates, Labour women, Labour youth, Maori, Pasifika, gays and so on - start working for the party rather than feeding off it.
He will promote on merit, not quotas. He intends to transform a seriously flabby political institution into a slick political machine.
That will not be easy. Shearer's victory has put some noses out of joint. His first moves will be conciliatory, especially in Cunliffe's case.
David Parker will get Cunliffe's job of finance spokesman. But Shearer will almost certainly keep Cunliffe on Labour's front bench.
The theory is that Cunliffe will find it difficult to get disgruntled if he has nothing to be disgruntled about.
For his part, Cunliffe has pledged "unconditional" support for Shearer as leader. That is an astute move. If Shearer crashes and burns, who would the party turn to then? Surely not the similarly inexperienced Grant Robertson, Labour's new deputy leader, who would be tarred by association with Shearer.
Presuming Cunliffe behaves himself and remains loyal, he would get the job by default.