That makes no sense to me, though. They can’t possibly have known TSP was going to be such a runaway success. By far the most likely outcome was that it would sell some copies and fade into obscurity.
Writing a ‘redemption via nature/walking’ memoir isn’t the obvious way to fame and fortune.
It makes no sense to me to see them as Bond villains orchestrating some kind of pre-planned campaign of deception for world domination (while stroking a Persian cat in their Vango and cackling.)
I think SW bodged together things that in reality happened over a period of years (repositioned diagnostic timeline moved up in relation to the eviction, primarily, but also, as seems likely, the walk conducted in bits over a much longer period than presented, including times when they were not even ‘homeless’ in the most technical sense), and I don’t think they were ever as indigent or desperate as is claimed in TSP.
SW had always had writing ambitions, so presumably wrote TSP out of these, was thrilled at the positive reception from agent/s, and that it then sold to a major publisher. I presume the ‘made homeless two days before a terminal diagnosis’ narrative was already in place when she queried agents and it sold to PRH, which is why it sold — excellent elevator pitch.
But its success takes them both by surprise, and they had to deal with way more scrutiny and media attention asking the same questions than they’d ever expected, and SW found herself under pressure to hit the same note in sequels (ill Moth, spousal adoration, nature, walking, lessening in his symptoms). The initial omissions, deceptions and rearrangements for dramatic effect of TSP had by now hardened into a much more elaborate set of lies, and, stupidly, they keep compounding them. Then the film was made, far more people suddenly knew about TSP and their story, and someone with suspicions contacted a journalist who started digging.