Maturity

What the heck does this word mean? Does it mean that your brain starts to churn and puff a lot more harder for simple and straight forward solutions.. Does it mean that you need to run through a whole list of "what ifs.." or "will theys.." for just turning your head left?.. Does it mean that you can no longer say something straight forward and place hundreds of speech transformation devices before a word comes out of your mouth. Well.. what the heck is maturity?