A few months ago, a MacBookPro became my working machine. As a long time Linux user, I’m pretty much used to case sensitivity in everything I do. Like searching in a man page, for instance. If I don’t remember the meaning of ‘-l’, why should I care about ‘-L’? So, if you’re like me, you might wanna have a look at /private/etc/man.conf at the lines

PAGER        /usr/bin/less -is
BROWSER      /usr/bin/less -is

and remove the -i options.