anyone can achieve CCIE, it is a matter of hard work and many hours of practice...
networking isn't difficult, it is just a matter of understanding what is happening behind the scenes. Someone aged 18 has enough brains to understand what is happening, especially if you're a bright kid.
I'm currently busy with diving into the CCIE lab exam... and yes it is difficult, but i must admit, with my experience and previous cisco certifications (knowledge) I am not really scared by the exam topics...
CCNA / CCNP / CCNA - Security / CCIP / Prince2 / Checkpoint CCSA