You know what it's like - you install a gem and are confronted by minutes of this:
Installing ri documentation for bananas-0.4.9... Building YARD (yri) index for bananas-0.4.9... Installing RDoc documentation for bananas-0.4.9..
I never look at the docs on my local machine, I either read the source, or look up the docs online. So why bother installing all those docs?
Edit your ~/.gemrc file and add the following lines:
install: --no-rdoc --no-ri --yri update: --no-rdoc --no-ri --yri
Boom - no more updating your docs - installing gems just became RIDICULOUSLY FAST.