I wonder whether it is the relative pronoun
Truth be told, I never graduated from college, and this is the closest I've ever gotten to a college graduation.

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In this clip from Steve job's speech in Standford school, I wonder what is the part of "the closest"? Do I see it as the adjective, dropping the pronoun "one"?

I think it should be like this: this is the closest one (that) I've ever gotten to a college graduation.

Right?

If that's the case, should I think "the closest" is basically the object of a verb "have gotten"?

Then, what is the meaning of "get" in here?

Question

I wonder whether it is the relative pronoun
Truth be told, I never graduated from college, and this is the closest I've ever gotten to a college graduation.

----

In this clip from Steve job's speech in Standford school, I wonder what is the part of "the closest"? Do I see it as the adjective, dropping the pronoun "one"?

I think it should be like this: this is the closest one (that) I've ever gotten to a college graduation.

Right?

If that's the case, should I think "the closest" is basically the object of a verb "have gotten"?

Then, what is the meaning of "get" in here?

Answer

"Closest" is a predicate adjective here--it's describing "this," connected by the linking verb "is." "Have gotten" is the verb of a dependent clause that starts with "I've."

About predicate adjectives: http://grammar.about.com/od/pq/g/predadjterm.htm

Answer

"Got" here means "succeeded in reaching [a goal, a point, a destination].

Answer

"The closest" is a superlative used as a noun.  It is a noun.

A similar example is:  This movie represents the best of Hollywood cinema.

Another example:  The First World War wiped out the finest of the land.

Another example:  This is the best I can afford.