Subject: Why has the moon not been colonized?

I keep on trying to enter a  certain question, but it says be 
more specific. I'm being as specific as i can  possibly be! Here 
is the question.  Why haven't we colonised  the moon? We 
obviously have the  ability so why haven't we done so?Someone 
mentioned to me the matter of  cost.If this is the case, why 
couldn't we make it a commercial venture, ie  charge people to 
live there.For example, you could have an old age home  
there(better gravity, longevity etc).Also tourism would provide a 
lot of  money, and finially, the moon could be the launchpad for 
all our ventures into  the solar system.The lower gravity on the 
moon would make journeys more cost  effective to mars etc. So, 
what's the story?  Thank you for your help in  advance.

Re: Why has the moon not been colonized?