My understanding is that the Maester Aemon from GoT is Egg’s older brother.

And the grandson of Egg is the mad king. But in the one mad king vision from GoT, my recollection is that the Mad King himself was quite old before he gets killed.

If this is all accurate, is Aemon supposed to be like 130 years old when he finally croaks up at The Wall? The equivalent of his grandson was also an old man several years earlier based on how the Mad King was presented in the series.