The randomness of when desire raises its selfish head can be jarring. You immerse yourself with the ephemera of life; jobs, family, and even in this little ice age, weather: Accept sanguinely the dog days of January. You board a train, content that it will bring you from A to B almost on time, you are receptive to the embrace of the Sunday papers.
In retrospect the first fifteen minutes in the same carriage passes unremarkably. It's as if the body inevitably has to get used to new surroundings and takes its pretty time to shed its January torpor. Lust initially materialises in a linear and streamlined fashion. First off wryly recognising the irony of being attracted to a younger version of yourself: The incarnation that had no concept of his possible attraction to others. You're also though slightly irked by his slight similarity to a gentlemen of your acquaintance that you've never had much time for, and whom you've never consciously been attracted to.
You ease your way in by admiring, in a catholic sense, his young fogey, sartorial elegance. He evinces a high forehead crowned by a thick red halo of hair: Does he realise that he will shortly be balding. You try to reassure him telepathically that fretting would be a waste of energy. After all many men ( for it must be men ) will only see it as a boon.