I’m a Julie and I love my name - I’m in my 30s. I don’t meet that many people with this name, but it is a well known and international name.
Funny that PP are saying it’s an old lady name, I’m from France and I know lots of Julies my age (at one point at school we were 3 Julies in the same class) however I don’t know any older ones. Different countries, different name trends I guess!