the first/last to do something

be the first (person) to (do something)

To be very likely or eager to do something. You know I'd be the first to help you out; just ask me next time. She'll be the first person to admit that the program has flaws, but she still believes in it very strongly.
See also: first

(be) the ˈfirst/ˈlast (person) to do something

be very willing or likely/unwilling or unlikely to do something: I’d be the first person to admit that I’m not perfect.Mary is the last person you’d see in a pub — she hates pubs.
See also: first, last, something