Why do i stutter??

Why do i stutter?? Some context: I'm pretty extroverted most of the times, and don't have much social anxiety. I'm a in the 18-20 age (prefer not to post actual age), and i talk fast, and alot. Recently i've been noticing i stutter ALOT. i don't understand why, as while i know i've stuttered a bit in the past, every time im speaking i a public setting i'll notice it. I don't mind too much, but it's strange to me that i started stuttering as much as i have of late later in my life (google says most kids develop it under the age of 7) and was wondering if anyone had any clue.