I'm 45. I've found that stuttering comes and goes for me in multi-year waves. 4-5 years. Elementary school was bad. Junior high and early high school were a lot better. Late high school it started to get bad again through the first couple years of college. There have been times where for a few years in a row I was almost entirely fluent. But it always returns. I'm coming off a 4-year fluency cycle and can feel stuttering starting to be come more prevalent again. At this point I'm used to it. I'm confident that the cycles will continue. I've been unable to correlate them with any particular life events. Just kinda comes and goes.