Answer:
my birthday
Explanation:
Its weird cause it's a day that I turn another number/age
Assuming we're just looking at this phrase, "learn'd" suggests that the astronomer studied to become intelligent in the astronomical field.
It is John Gardner's novel "Grendel" from 1971 that initiated the trend of telling a story from a monster's point of view. The story is essentially the epic poem Beowulf spoken trough the eyes of Grendel