Chronology in IV

[John Bailey]

I have to admit, the particulars of IV's timeline are a bit confusing
for me. Not most of the novel, just a few details:

Doc hasn't seen Shasta for over a year (p.1)
They weren't an item for very long (p.11).
Doc says "You know I have an office now?" to Shasta - he could be
joking, but if not it sounds like he got the office within the past
year.
"A couple of years ago" (p.25) he was doing matrimonials.
Before that, I guess, he was a skip tracer.
Shasta and Doc were together before he became a skip tracer,
presumably not long out of high school (p.11)
Now he's almost 30.

What I'm not sure about: that's a long time between drinks, Doc. If he
saw her a bit over a year ago, I'm assuming there was still some kind
of contact between them all that time? And boy, is he still hankering
after her, what, up to a decade or more later? And she's still known
as his ex-old lady? This loser has got it bad.