According to X means in “X’s opinion”, “if what X says is true”.
According to Harry, it’s a good film.
The train gets in at 8.27, according to the timetable.
We do not usually give our own opinions with according to. Compare:
According to Ann, her boyfriend his brilliant.
(=if what Ann says is true=)
In my opinion, Ann ‘s boyfriend is an idiot (NOT
According to me,…)
From Michael Swan, Practical English Usage, Oxford