I second (third, whatever) what the girls have said about photos.
I was sure I hadn't lost anything and looked the same. Until I took photos. And the difference is huge! (pun intended!)
So if you have photos of yourself at your heaviest and now, check them out side by side. I did it in the same pose and clothes, but you don't have to do that.
For the record, I still think I look the same! My brain won't process what my eyes are telling me. But it's there.
Here's my blog post with the pics in it, if you like.
My before and during photos.
Cheers!