You're a Bongistani, aren't you? Britain has always had the highest AOC in Europe and also the highest age of not being a child anymore. Legally speaking, not personally (and yes I absolutely did feel immature at 14, 16).
Some European legal systems tackle this differently; Eastern Europe usually makes the cutoff for "child" at 14, and then after that you'd legally be an "adolescent" or "older minor" up to age 18 which means you get some of the adult rights and legal responsibilities, up to and including being able to consent.
Once again, this is all strictly speaking legally, not from a moral standpoint - that's where I'm clearly on the side of "look for something your age, weirdo" for pedos.