I don't think it's strange at all. I think that doctors are in a quandary - the "old" way of telling anyone with a spare ounce of fat, that any and all of their health issues are caused by fat and they need to lose weight before they can receive any treatment and the "new" way of ignoring weight issues - well neither have worked very well.
I've had doctors that I can't help but think if I went in to their office with a steak knife stuck in my eye, they would have blamed it on my weight and refused to treat it until I lost 100 lbs. I've had others that when I mention wanting and trying to lose weight, they shrug and say "don't we all."
I remember my first successful weight loss attempt in high school, my goal weight was 150 lbs. I got down to 155 (down from 225 in 8th grade when I started). The weight was coming off very slowly, and I wasn't sure I was going to ever make it to 150, and my doctor pulled the rug out from under me and told me he was changing my goal weight to 140. I pretty much snapped, and gave up entirely. My senior year was spent regaining, and I entered college at 250 lbs. I'm not blaming the doctor, I chose to freak out over what someone else thought of me. At 17, I still thought doctors knew everything, but I could have chosen to stick it out, and cross that last bridge when I came to it.
Last fall my husband and I joined TOPS. TOPS requires you to have a goal slip signed by your doctor on file, so at my next doctor's appointment I asked my doctor for one. He asked me what I thought it should be, and I said 200 lbs. He winced and suggested that I reconsider. I of course thought he meant the weight I suggested was too high. I explained that I thought I would get there and then decide if I could lose more, and I learned that he thought my goal weight was too low. He suggested 250.
So my story is pretty much the same as yours, only I had a completely different reaction to it. My doctor was recognizing that losing 144 lbs would be an incredible accomplishment, and that if I never lost an ounce beyond that, it was still an incredible accomplishment. Losing weight isn't an all or nothing endeavor, and success isn't only measured in how close you can approximate a super model.
Now, I don't plan on remaining at 250 lbs. I think I can do better, and I'm sure that when I reach 250 lbs, my doctor will agree. The thing is I'm excited to have two goal weights. The 250 that my doctor envisions, and the 150 lbs that I do. In fact, I like it so much, I'll probably split the difference and consider 200 lbs my third goal weight. In some ways, you could even say that I have almost 200 goal weights, as I use a sticker chart for myself and every pound is a sticker, and I give myself a little reward at every 5 lb mark, and a bigger one at every 20 lb mark.
This time is different than any other I've attempted, because I've decided this time that only giving up and backsliding is failure.
Don't get hung up on your ultimate goal at this point. Start with the nearest number you can stomache and get to that. Celebrate it, maybe even practice maintenance for a bit, and then take on a bit more.
