I point out in several posts that one reason I will walk away from an author/series is the abandonment of the character. That is, the author starts using a character for an often completely unrelated agenda by giving the character attitudes and behavior inconsistent with the character's earlier attitudes and behavior.
The issue here is complicated by the fact that people do change.
They change in terms of age. They change in terms of focus (what they care about, what they have time for). They even change by improving: shedding bad habits; acquiring good habits; treating others' better; treating themselves better.
In Niffenegger's Time Traveler's Wife, the wife is at first somewhat disappointed when she meets her husband in chronological time. He isn't the older, wiser, gentle, mature guy she has grown up knowing. She knows what is coming, however, and waits for him to become that guy.
Generally speaking, I do not advocate marriages built on "in the future, she/he might...." In this case, what Clare knows about the man is something of a given. She still takes a leap of faith. But she isn't signing up for a complete unknowable.
And, from a writing point of view, Henry doesn't instantly become somebody else. He is THAT guy, simply younger.
What keeps a character a character, even while that character matures?
In my review of "Humbug," a Scrooge-tribute, I wrote that the novella succeeds because the author, Joanna Chambers,
doesn't abandon the (thirty-odd) Scrooge's base personality:
Chambers characterizes her thirty-something Scrooge, Quin, as inherently
obsessive. That is, his personality is such that no matter what he
does, he has to go at it to the nth degree. He gets into the consulting
game by accident but once he is there, of course, he's going to be the best consultant ever whose team is also the "best". He's on the fast-track to becoming a manager.
Problem: the gig isn't totally in line with his personality, so he
becomes--as characters in the story repeatedly tell him--a "dick." He
later tells Rob, the Bob Crachit character, "I think [this job] brings
out the worst in me." Instead of becoming the kind of leader whose team
is the best because they admire him and feel appreciated, he becomes
(is becoming) the kind of leader who wrings work out of people through
unreasonable demands and sheer sarky irritation. He is acting in
accordance with what he believes to be the "role" of manager--and he
does it well, but it makes him absolutely unpleasant to be around.
After his epiphany, he returns to his first plan to be a math teacher.
And here is where Joanna Chambers really knocks the characterization out
of the park: because
of course, Quin has to be the BEST teacher. Only this time, what he
wants and what he brings to the table are in line. He'll get in his
students' faces ("They'll love you," Rob says, "because you're
sarky"). He'll get in their parents' faces. He'll tick off the school
board but still win. The aggressive energy that makes him unlikable in
one field (that he doesn't feel at home in) will make him an excellent
advocate in another.
That is, the triumph (and difficulty) of the character who changes is that the character remains the character, only better.
A spouse can get better--but not because the spouse turns into someone else. The spouse is THAT PERSON improved, not "what I really wished I'd married instead."
