Right now I’m doing something I don’t believe I’ve ever done before: pack for two trips at once.

Tonight, I hop across the pond as the Western world sleeps, bound for London and a two-week visit with my visiting-professor mother. (A quick shout-out: her blog can be found here.) There will be museum-going, geocaching, hiking, and quick trips to Wales and Scotland.

Afterwards, I’m traveling direct to Denver, CO, for a cousin’s wedding and another week and a half of fun with a good friend who lives in Breckenridge. Country-club posh and ski-town ritz.

The ordinary grade-school math of packing has suddenly been transformed into algebra. How do I combine my innate urge to pack light with the need for gear for multiple purposes? Why am I having such a hard time grasping the idea that I’ll be gone for a month? Can you fit a suit in a rucksack?