Commando,
I don't agree with your last statement.
I never picked up a racket until I was almost 50 (except for maybe 5-6 times at family gatherings, etc.). I started playing in August 2005 and by the end of year had won 3.0 tournament and was finalist in 2 others. In 2006 moved myself up to 3.5 and promptly lost my first 13 matches. I'm winning about 60% of matches now. NOTE: I had some physical problems in 2006-2007 that I've yet to totally recover from.
While I'm not an "amazing" athlete I did play basketball in college and have been very active my entire life. So I think someone that is as or more athletic than me can easily start at 3.0.
I do agree that if a he is beating his friends they are not 3.5. They may think they are but they are not.
I may be wrong. In any case, starting out at 3.0, while maybe not impossible, is definitely rare. Kudos to anyone who can do it.
Yeah, the thing about his friends being 3.5, I think it's a good chance they may be (unintentionally) overrating themselves, which happens a lot in tennis. Players who don't participate a lot competitively, I feel, look at the NTRP rating guidelines, see the 3.5 "qualifications" and think, "Yeah, that's me." Then they get on the court with some real 3.5s and it's a different story---no disrespect to the OP or his friends.