BrainDump: irb - require returns LoadError: no such file to load

Situation:

irb(main):011:0> require 'json'
LoadError: no such file to load -- json
 from (irb):11:in `require'
 from (irb):11
 from :0
irb(main):012:0> require 'rubygems'
=> true
irb(main):013:0> require 'json'
=> true
irb(main):014:0>  

Solution:
Do

require 'rubygem' 

before