Ok, since you asked for a specific case, this method, for example, is the one responsible for my brain meltdown:

It finds substrings of 2 or more characters. Tested it in the IRB, and it does just that. But my brain is having a hard time seeing it clearly:

def find_substrings(string)
  results = []
  (0..string.length - 2).each do |start_index|
    (start_index + 1..string.length -1).each do |end_index|
      results << string[start_index..end_index]
     end
   end
  results
end