Live as on a mountain

Marcus Aurelius (Roman emperor 161-180) has some very odd advice: ὀλίγον ἐστὶ τὸ ὑπολειπόμενον τοῦτο. ζῆσον ὡς ἐν ὄρει. Roughly translated this means, "life is short and you should live your life as if you were on a mountain". One is inclined to ask why; what is so good about living on a mountain? Note also that he does not tell us to live on a mountain, but as if we were on a mountain. In fact he assumes that we do not currently live on mountains (since you cannot live as if on a mountain if you are already living on a mountain). Perhaps in those days you could not live up a mountain. One suggestion as to what he means is that it is great to live on a mountain and if your current life is confined by work, overcrowding, and so on you need to count that life as no whit worse than living in the free and unconfined atmosphere at the top of a mountain (this is the view of the Loeb translator, C. R. Haines). Martin Hammond (Penguin Classics) suggests that Marcus is combining the idea of retreating from the world with that of the irrelevance of local habitation to wider citizenship of the world. It is true that in the next sentence he says that it makes no difference where you live if you take the whole world as your city. But this seems a strange non sequitur since if local habitation is irrelevant why must you live as if on a mountain?