Most of our interviewees had experienced some periods of financial stability.
So what happens if something unexpected happens to one of our interviewees in the intervening period?
Only one of our interviewees is female, a fairly accurate representation of the demographics of homelessness.
However, "once a criminal, likely to be unemployed" was the conclusion drawn by one of our interviewees in Birmingham.
While making a follow-up Panorama in 2010, we became aware that some of our interviewees had met the FBI previously.
Some of our interviewees, particularly from ethnic minority groups, have asked for their identities to be hidden, fearful of the reprisals should their sexuality become known.
While filming, we were surprised at the number of women willing to talk; we actually had to cut out about half of our interviewees.
In fact, some of our interviewees felt that they got on well, but because they were the right sort of "female chap", as one put it.
Only an hour earlier, I had been in Manchester at a graduate recruitment fair, where nine out of 10 of our interviewees were supporting remain, and some voices spoke about leave voters with a cold superiority.
One of our interviewees, James in Uganda, is desperately poor and lives with his elderly father in an inadequate shack very close to a tea factory supported by Fairtrade.
In the course of recording the documentary, I was surprised when two of our interviewees - the leading Satie scholars, Ornella Volta and Robert Orledge - both said that they wouldn't have wanted to meet the composer.
