Years ago, when I was a kid, I started reading some kind of fantasy novel, and never finished it. I remember enjoying it, and would like to finish it - but I can’t remember the title.
The only distinguishing characteristic I can remember is that the mages appeared human, and aged normally, like humans do, but they were actually immortal. Once they grew old, they’d somehow travel to another world and “rest” - and then emerge as young again.
Only if they were somehow prevented from entering this other world once they grew old would they actually die.
There might have been some other factor - I’m not sure if time is what aged them, or if it was the actual use of magic. I think it may have been the latter. In any case, as they grew older, it took more effort to use their abilities.
Anyone know what book this is? I can’t remember anything else about it - I don’t even remember if it was meant for adults or children.