How to fix: RVM does not offer recent Ruby versions

RVM needs to be updated regularly to know of Ruby versions released since installation (or last update).

So if you say rvm install 1.9.3, but get an old version (basically anything below 1.9.3-p385 when writing this card), your RVM is outdated. \
Fix that by saying:

rvm get stable

After that, rvm install 1.9.3 should install the latest 1.9.3 version.