What is the best way to insert my age in the following sentence?

Question

"When I was 25yrs old / 25 years-old / 25 year-old.... I entered a university building at night through an open window with the intent of burgling it as I wanted to get myself sent to prison" how does one insert there age in the correct way, hyphens e.t.c?

Answer 1

You have a few options-

When I was 25, I wanted to go to prison so I attempted to burgle a university building.

At age 25...

When I was 25 years old, .....

Answer 2

Depends, really, on how formally you’re writing, but that’s mostly about spelling out “years.” Kate indeed has an excellent suggestion if the age is just an added data point to a story about the burglary. But if the age is highly significant, such as in a paragraph between stories about the narrator’s teens and those about settled years in the 30s, and formal writing, you’d need no hyphens, just When I was 25 years old, ...