At will take all four years of college/university for you to master each and every subject.
Don't expect to learn everything in a year, that's why college is four years long.
Trying to learn everything in a year is a Sisyphean task
1. It will take all four years of college/university for you to master each subject.
take (time) > (時間を)費やす
four years of college > 大学4年
master each subject > 一つ一つの科目をマスターする
2. Don't expect to learn everything in a year, that's why college is four years long.
don't expect > 〜期待するな・しないほうがいい・すると台無しになる
learn everything in a year > 1年間で全てを学ぶ
college is four years long > 大学は4年もある
3. Trying to learn everything in a year is a Sisyphean task.
1年間で全てをマスターしようとするのが果てしない無駄な仕事(石を山の上に運ぶシシュポス王のような)
ニュージーランド 
