Age 40 feels quite significant... we make a pretty big deal about it in our culture, particularly for women, I'd say.
I'm not sure how I feel about turning forty. On the one hand I feel like a big loser because I'm so un-accomplished at this point in my life... I was considered a likely-to-succeed kind of child, typically performing at the top of my class and all of that. But I've always had a flighty, unfocused side to me, and I'm kind of a perpetual kid. So I haven't had any huge success career-wise or salary-wise and I haven't used my creative side to its fullest so I feel kind of "meh" being 40 and not being able to list some amazing list of accomplishments. Some of my minor accomplishments that I feel happy about were more personal ones-- like going back to school at age 37 and becoming a gemologist and starting a new, rather low-paying but very fun career... completing a Bikram yoga challenge, etc.
School was one of the best things that happened to me in my 30's. Becoming close to my mom again after several big rifts throughout my life was another dramatic, positive change, my friendship and love relationship with Jake was an enormous life change, and my cool female friends seemed to be a theme of my late 30's, too.
I am often assumed to be ten years younger than I am, so I can't whine about my 40th too much. I don't really know what "the secret" to that is. Aging is, in part, genetic. I did two "cosmetic" things in my 30's which I think really make me feel young - I had Lasik vision correction; I went from having 20/400 vision and dealing with my glasses and contact lenses to having perfect 20-20 vision. I had my teeth whitened by my dentist using Zoom whitening. They were pretty white already but I read something about teeth darkening in your 30's and I panicked and did it, now my teeth are really white. Not fake white, but really white for natural teeth. I'm SO happy about both of these procedures and feel like having perfect vision and white teeth make me feel really young.
So far I haven't seriously thought about any Botox or fillers because I don't think I need them yet.
So, goodbye to my 30's and hello to my 40's!