Setting Realistic Expectations

What's wrong with setting a goal that may be a bit of a stretch? You think he would ever achieve it if he didn't dream it first? Though it doesn't sound like his work ethic and "once a week" training sessions will make it possible...

I also hear people, in their first season of running say "Oh I bet I can run a marathon in September" And through my affiliation with Team In Training, I've seen dozens of people do it. Don't recommend it, but it's very doable. But you do have to envision it first, the be willing to put in the time to accomplish it.

But isn't that what you're doing?  You posted that he made disparaging comments about you doing a triathlon, and now you're posting about his 'unrealistic' expectations.  Maybe he CAN get to 7m/m by next summer.  (And maybe I can swim 1.5k in 20 minutes...)  I don't see a question in your post; do you have one, or are you just looking for support for your thoughts?

Depends who you are.  If you're Lance, that line is MUCH higher than the average person's.  Right now, I have a goal that's higher than my SO is willing to support.  That's just making difficulties for us.  I suggest that you support him, show him www.halhigdon.com for training info, and see what happens.  When he doesn't make his goal, don't you DARE use the 'I told you so' line, and instead help him realize just how far he did come.

The real initials never caught on with the marketing people.

If he's motivated, eats right and trains consistently, I wouldn't bet against him. I'm 41, smoked for 26 years, my weight was 20-30 lbs more than it is now for some time. I had zero athletic background or experience after the age of 12. My innate physiology is by no means anything but average.

I started running in September of 2003 doing 12-13 minute miles and in June of this year I did a 3.5 mile race in 24'36" (a 7'02" pace). 

His goal is entirely reachable, and making improvements in performance for a few years is certainly possible. Barring injury, I fully intend to. When asked about this, Mark Allen replied to the effect that if one is just starting out, it's reasonable to expect improvements for 5 years or more regardless of age.

It was 1.75 years and included periods where I was sidedlined due to illness, injury and/or surgery. I agree that it's a bit of a stretch, but for the average person I don't believe it's impossible if they're motivated, don't get hurt, eat well and train smartly and consistently.

You peed in his Wheaties! I wouldn't run with you. Talk about sucking the joy out of dream.

If someone told me that my response would be:

Go for it! What an ambitious but attainable goal. Let's get there together. Do we need a plan or shall we wing it?

Which was the absolute correct response. He should call you "Coach".