Hm, this is interesting because creativity is sort of a set of peaks and valleys. Sometimes you'll hit your stride, only to fall flat on your face and have to recreate yourself or make something new, so in that vein its hard to judge where you really 'get it together'. Since art is a life-long journey, it's hard to quantify in this way. That being said, 'known for' is another matter.
I've always been 'known' as the artist. When it comes to personal strides or a groove though, mine had a couple of starts. (And I'm also no Terry Pratchett so, who knows if the feeling is different after a certain level of notoriety) When I was 9 I started my first comic and when I was 13 I finished it. It was over 1000 pages and had seven generations of characters (as I tend to move on from one group to the next with a beginning, middle, and end with each group and following through). When I was 14 I started my first novel and when I was 16 I'd finished the trilogy and a host of short stories. I'd also started my tattoo business (so I could buy a Gamecube, yeah, yeah, get your laughs out now) and I did commission work. So those were my separate grooves where I felt (each time) that I had it all 'together' as it were. (Hah, usually at the beginning of a project when I could secure a false sense of bravado about what I was doing.)
I won't go down the entire laundry list but, my creative path has lead me to run my own shops both online and IRL, participate in adjudicated galleries (every time I've submitted work I've had a piece up in the main gallery, which can be difficult when upwards of 300 pieces are submitted and only 50 are chosen), meet and take a painting class from the head of the DreamWorks art department, write and self-publish a children's book, started another trilogy (working on getting proper publishing done for that one), and ultimately this has continued throughout every job I've had, any schooling I've done (all for other things, as I work primarily as an editor), and through it all as I've gotten older, my bravado has melted and I can tell you 1000% I don't personally feel like I've really had anything 'together' looking back despite hitting several grooves where I felt I'd done good work.
I don't know if I'll ever feel that way. I think if I felt like I had my shit together, I'd be worried that I was doing it wrong hahahah. I've a very long way to go with my digital skills, alas. I've worked with physical tools all my life (paint, ink, clay etc.) so, yet another start was when I was 17 and in college and figuring out digital tools on my own. I'm waaay not the best at it and I'm doing what I can to acquire new skills and as always, I feel like I'm flying by the seat of my pants. My hope is that some day, I'll have made something that inspires others. Dunno when that'll be, if that'll be, but I like the idea. Maybe someday I'll know how Terry Pratchett felt. 