This is the best summary of project costs I've read. It applies, as the author said, to private as well as public projects.

"Never mind the fact that that single program alone accounts for about 1/3 of the US deficit."
Not true. in 2010, SS will add $10B to the deficit. The deficit is projected to be above $1T, resulting in SS being 1%, not 33% as you claim, of the US deficit.
http://www.google.com/hostednews/ap/article/ALeqM5h6BfoloJOnV0TeI7eIHC1ZWuBxygD9AVLTVO0

"Think about that for a minute - you have to be 65 to collect, and the average life span is in the upper 70's"
Average life span is a tricky measure. Many people die as the very young or as teenagers. A much smaller percentage of people die between 18 and 80. If you've started work, there's a better than even chance of you collecting your social security.

like a bad loan?

The Obamas gave the Queen a rare signed songbook by Rick Rodgers, or Rodgers and Hammerstein fame. Rodgers is one of the greatest American composers. The iPod was filled with his music. It was a thoughtful, expensive, classy gift.