Six to twelve months, with permit systems creating hard-dated release moments that behave exactly like a ticket on-sale. Training begins at booking, which means the customer relationship is a year long before the trip happens, and almost nobody uses that year.

Operator departure groups formed before the trip, charity challenge cohorts, permit systems, and forums where people research obsessively for a year before booking. Train for months with a friend or a spouse who is going too, fundraise, form a WhatsApp group with strangers assigned to the same departure, and stay in touch afterwards with an intensity that surprises them.

Permit release dates rather than events. The trek, acclimatisation days, base camp, a teahouse, the summit push, the pass, porters and their welfare as an ethical subject, AMS, a rest day, going high and sleeping low.

The monsoon months of June to September in Nepal, and the Andean winter. These are absolute rather than soft: the routes close.