Learn Hardcore Japanese: syakaizin ni natte kara, gakusei no koro yori zutto mazime ni zikan wo kanrisuru you ni natta. - After becoming a working adult, I’ve come to manage my time much more seriously than when I was a student.

University students are technically adults (大人), but people usually don’t call them 社会人 yet. In this sentence, the nuance is “after I started working as a full-fledged member of society.”

Why is there a に after 社会人? What does 社会人になる mean?

X になる is the standard pattern for “to become X.”

社会人になる = “to become a working adult”
先生になる = “to become a teacher”
有名人になる = “to become famous / a celebrity”

Here:

社会人になって is the て-form of 社会人になる, used to connect to から.
Literally: “after becoming a working adult…”

So に marks the resulting state that you change into.

What does 〜てから mean in なってから? How is it different from just なって?

V-てから has two main meanings:

“After doing V”
“Since doing V” (and that change continues up to now)

So:

社会人になってから
= “After becoming a working adult / Since I became a working adult”

If you just said:

社会人になって、学生のころより…

it could still be understood, but 〜てから makes the “from that point onward” meaning very clear and explicit. It emphasizes that the change in behavior started at that time and has continued since.

What does 学生のころ mean? How is ころ different from とき?

学生のころ means “when I was a student” or “back in my student days.”

Noun + の + ころ = “around the time when I was N / that period in my life”

ころ and とき are close in meaning, but:

ころ often implies a more general period or phase in your life
(e.g., 学生のころ, 子どものころ = “when I was a student / a child (in general)”)
とき is often a more specific time point or situation
(e.g., 学生のときこの街に引っ越しました = “I moved to this town when I was a student.”)

Here, 学生のころ sounds like “in my student days” rather than a single moment.

How is より working here in 学生のころより?

より is a comparison marker:

A より B = “B (is) more … than A”

In this sentence:

The “A” part is 学生のころ (“my student days”)
The “B” part is the current state (now, as a 社会人)

So 学生のころより means:

“than (I was) when I was a student”

The full comparison is essentially:

(今は) 学生のころよりずっと真面目に時間を管理するようになった。
= “(Now) I’ve come to manage my time much more seriously than I did when I was a student.”

The “now” is understood and omitted.

What does ずっと mean here? Is it “always” or “much more”?

ずっと has a few common uses:

“The whole time / continuously”
“By far / much / a lot (more/less/etc.)”

In this sentence it’s use (2):

学生のころよりずっと真面目に
= “much more seriously than when I was a student”
= “far more seriously / way more seriously”

It does not mean “all the time” here. It’s emphasizing degree: not just “more serious,” but “much more serious.”

Why is it 真面目に and not 真面目な? What is this に doing?

真面目 (まじめ) is a na-adjective:

Attributive form: 真面目な人 = “a serious person”
Adverbial form: 真面目に勉強する = “to study seriously”

To modify a verb, na-adjectives typically use 〜に:

真面目な → 真面目に (serious → seriously)
便利な → 便利に (convenient → conveniently)
静かな → 静かに (quiet → quietly)

Here:

真面目に時間を管理する
= “to manage (one’s) time seriously”

So 真面目に is an adverb meaning “in a serious, earnest way.”

What does 時間を管理する literally mean? Is this a common way to say “manage my time”?

Yes, this is a natural and fairly standard phrase.

時間 (じかん) = time
管理する (かんりする) = to manage, to control, to administer

So 時間を管理する literally = “to manage time,” often understood as “to organize / control how you use your time,” i.e., time management.

Other related expressions:

時間を大切にする = to value/treasure your time
時間を無駄にしない = not to waste time

But for the idea of “time management” in a structured or professional sense, 時間を管理する is very natural.

What does 〜ようになった mean in 時間を管理するようになった?

V-dictionary-form + ようになる expresses a change in habit, ability, or state over time:

食べるようになる = come to eat (something regularly) / start eating (something)
行くようになる = start going / come to go (habitually)
話せるようになる = become able to speak

So:

時間を管理するようになった
= “I have come to manage my time”
= “I (gradually) started managing my time (as a new habit)”

It’s not just “managed my time once”—it implies that managing time has become your new regular behavior.

Why is it なった (past tense) if the situation is still true now?

Japanese often uses the past tense to indicate that a change has occurred and the new situation now exists as a result.

So:

〜ようになった = “came to (do/be X)” → the change happened, and this is now the current state

In English, we might use the present perfect:

“I have come to manage my time more seriously”
“I’ve started managing my time much more seriously (and I still do)”

So even though なった is grammatically past, it includes the idea that this new way is now in effect.

Where is the subject “I” in this sentence? How do we know it’s about “me”?

Japanese often omits the subject when it’s clear from context.

This sentence has no explicit 私 (I), but:

It describes a personal life change: becoming a 社会人, comparing to 学生のころ, managing one’s own time.
In typical conversation, the speaker is usually talking about their own experience unless context says otherwise.

So the subject is understood as:

(私は) 社会人になってから、学生のころよりずっと真面目に時間を管理するようになった。

The omitted 私は is recovered from context and is naturally translated as “I.”

Could we use もっと instead of ずっと here? What’s the difference?

You could say:

学生のころよりもっと真面目に時間を管理するようになった。

and it would be grammatically correct. The nuance difference:

もっと = “more” (neutral strength; just comparably more)
ずっと = “much / far / way more” (stronger emphasis)

So:

ずっと真面目に ≈ “much more seriously,” “way more seriously”
もっと真面目に ≈ “more seriously” (without that strong “by far” feeling)

In this sentence, ずっと sounds more emphatic, highlighting a big change from student days.

Is the word order around より and ずっと fixed? Could we move ずっと?

There is some flexibility, but what you have is a very natural pattern:

学生のころよりずっと真面目に時間を管理するようになった。

Common natural variants include:

学生のころよりずっと真面目に… (same as given)
学生のころより、ずっと真面目に… (just adds a comma/pausing)

You might also see:

学生のころより真面目に時間を管理するようになった。
(no ずっと; a weaker comparison)

Putting ずっと somewhere far away from より can sound off or ambiguous. The safest and most common is exactly as in the sentence: [A よりずっと B].