How fair is that?

I went to the gym last night. I was feeling so blah after all of the sugar I had consumed over the weekend in honor of Valentine' Day that I knew that I had to go. I love going to work out; it just hasn't been as easy to do over the past few weeks with sick kids and potty training. However, yesterday, I had new determination. I must lose 5 pounds. Or else my 5 pounds will become 10, and then 12 and then... well - you know. So, I was on the elliptical machine which I HATE (all of the treadmills were busy) and one of the trainers I have worked out with came over to talk to me. His name is Mark and he is a BIG guy - not fat, but just BIG. Over 6 foot tall, and I bet he weighs about 275 pounds. Since I haven't been at the gym I haven't seen him in a few weeks - he is not BIG anymore - I could tell in his face that he had lost some weight. He told me that he's lost 33 pounds... IN 3 WEEKS!!! I couldn't believe it! I want to lose 5 pounds and can't seem to do it, he's lost 11 pounds per week??? I just can't understand it. I'm happy for him, but it is just not fair.