The Constitution of the State of Illinois explicitly defines the militia as made up of all able bodied citizens thereby avoiding the argument that it is only a collective right. It is unfortunate that the Constitution did not do the same although that declaration has not stopped Chicago from enacting onerous gun control legislation.
However, you are wrong about the first thirteen words in the Second are not a preface but rather an explanation for the right being mentioned. There was no need for any kind of preface before the stipulation of the right to own firearms. No "prefaces" were deemed necessary to the other amendments.
Be that as it may do you know of any actual discussion of the Second amendment by the Founders either at the CC or the Congressional debates?
http://www.usdoj.gov/olc/secondamendment2.htm
These are not MY words.
They are from the USDOJ.
Look it up so you will know what the acronym means and then read the link.
Is everything in your life as hard for you as reading seems to be?