I went with "I usually read only parts of the manual I feel are needed to operate it safely but not always," because it's closest to the right answer, but it's still not quite right. I can't claim to read the whole manual, because I always skip the parts that explain: if I hear something odd, I should take it to a gunsmith, if it fails to fire, I should take it to a gunsmith, if anything more than the slide needs to come off, I should take it to a gunsmith, etc., etc. I don't feel bad skipping that.
I also skip anything that explains to me how to use the included cable lock.
I also, admittedly, skip the portions of the manual that are restatements of the four rules.
I do, however, always read every word about the functioning and maintenance of the gun (where each control is, how to field strip the gun, which parts in particular need cleaning/lubing, etc.)