Two weeks ago Sunday, my iPhone 3GS slid from my pocket and nuzzled itself amongst the fossilized bubble gum, mottled receipts and other sticky detritus that lays thick between the seats of the 7:20pm MBTA train to Forest Hill on the Orange Line. Doubtless someone is playing with it even now. I didn’t even notice it go, but unlike the last time I lost my iPhone, my initial reaction was not panic or thundering rage, but a serene sense of acceptance: I just don’t need an iPhone anymore. I barely even tried to recover it. This is my new phone, and god help me, I love it.