I'm 24, and I'm still enjoying them. ♥
I don't think any hobbies/interest have an age limit. You either like something or you don't.
Some people decide that they are "too old" for certain things and that is just sad, because it's often not because they've lost interest- but because they feel other people will judge them.
And like Stefke2108 says, yes, there are some occasions where I too don't take them along, but that's because in some places people would think it was unprofessional... luckily, in my corner of business, many people find it creative and quirky.