I've had to deal with people who say exactly the same things to me over other issues. IE I had a supervisor say they understood how I felt wearing hearing aids and dealing with and ear infection because they had a single ear infection as a 6 year old! No.... not really the same as being Deaf, getting an annual infection (instead of a yearly cold etc) and having to shove earmolds in over a very painful one!
Anyhow, I do indeed understand the frustration behind it. The good thing is that there ARE people who can and do identify with your situation (case in point, all the awesome peeps here at Susan's!!

) But that guy, while his answer sounds overly practiced probably IS at least making an attempt to try and understand (or maybe he/she is in the closet!)
In the end, there will always be days when we are more sensitive to this stuff than other days. I came out to a friend who I THOUGHT would get it more than she di. It took her several days to get over what she thought of as me lying to her for 2 years; and I came out to my Dad who I though would take it hard, yet he was really cool about it.
My biggest piece of advice is to take it as positivey as you can, if he says he understands, you likely have an ally and a sympathetic ear (within reason), and those who THINK they understand (Like my example above) are at least trying! (Sometimes they can get VERY trying, but that's life.) Roll with it and if you can't let it roll of like water off a duck.
Here's hoping you have less dysphoria days in the future, they can be rough.