Why do people say 小学校の時 or 中学校の時?

Question

When reffering to the school days, people often say 小学校の時, 中学校の時. Even though this may not be wrong, they are shortened forms of relatively complex (redundant) structures. Thus, they are close to the expressions:

私が通っていた学校が小学校だった時
'when the school that I used to attend was an elementary school'
私が通っていた学校が中学校だった時
'when the school that I used to attend was a junior high school'

I think that there is a much simpler way to express the same situation, such as:

私が小学生だった時
'when I was an elementary school student'
私が中学生だった時
'when I was a junior high school student'

which would be shortened to 小学生の時, 中学生の時, and I do hear people (including myself) using the latter. But still, many people seem to be using the former. Why do people use a more complicated way of saying it?

Answer 1

Actually I don't find it surprising. It may be just my own experience but,

English:

[a] "When I was in (primary/secondary/middle/high/etc.) school......" (More common)

as opposed to,

[b] "When I was a (primary/secondary/middle/high/etc.) school student......" (Not as common)

Chinese:

[a] "(我在)[小/中/大]学時......" (More common)

as opposed to,

[b] "我[小/中/大]学生時......" (Less common)

Singlish (Singaporean English):

[a] "primary school that time..." or "that time primary school..." (More common)

[b] "primary school student that time..." or "that time primary school student..." (Almost not used)

Arguably the [a] versions are not specific enough, because you can be referring to any time period that you were in (the) school, regardless of what role you are. I.e. you could be a student, teacher, staff, random civilian, etc. The [b] versions explicitly state that it's the time of being a student.

Also the Singlish versions (if anyone can understand it) show quite obviously why [a] is preferred to [b]. It's just a shorter sentence, and everything else is deduced from context. Being a native speaker of Singlish without any formal study into it I have no way to analyse it apart from just simply feeling that it's correct.