I don't think you'll outgrow the trend because you've loved it for years! I think you'll continue to love it!
As for the age factor, I'm 34 so I kinda feel the same way! I do have 1 MC bag (Audra) and love it. I also love the Speedy! But most of the other bags I do feel I'm too old for! So, for me it really depends on which MC bag I feel is too young! If that makes sense!
I think you should get your white MC Speedy!