Not P but Moby-Dick (39)

[Mike Jing]

>From Chapter 54:

For my humor’s sake, I shall preserve the style in which I once narrated it
at Lima, to a lounging circle of my Spanish friends, one saint’s eve,
smoking upon the thick-gilt tiled piazza of the Golden Inn. Of those fine
cavaliers, the young Dons, Pedro and Sebastian, were on the closer terms
with me; and hence the interluding questions they occasionally put, and
which are duly answered at the time.

What does "For my humor’s sake" mean here?