Anyone else's stutter begin later?

Everything I read online says stutters usually begin in childhood, and then never address the possibility of it showing up later. For me, I either didn't stutter as a kid or was so carefree I didn't notice it. But my first memories of stutter were in freshman or sophomore year of highschool. Since then it has come and gone in waves, and I'm usually able to get by without too much worry, but sometimes I'll have just terrible days where I can't talk to a soul. Anyone else have it start so late? I've just never heard of anyone else start stuttering after childhood. (No I didn't have any kind of traumatic event or something that would have caused it)