Our actual enemy is not any force exterior to ourselves, but our own crying weaknesses, our cowardice, our selfishness, our hypocrisy, our purblind sentimentalism.
When traveling is made too easy and comfortable, its spiritual meaning is lost. This may be called sentimentalism, but a certain sense of loneliness engendered by traveling leads one to reflect upon the meaning of life, for life is after all a travelling from one unknown to another unknown.
Sentimentalism is the working off on yourself of feelings you haven't really got.