Oh yeah, for sure. This just happened a few weeks ago when i saw a colleague I hadn't seen in a few years. I was standing about 5 feet away from her in a line and could tell she look right past me without recognizing me. So I said hello and she "oh hey, I didn't recognize you!" That was the clearly the polite way to say, "wow, you got so fat." I guess I did put on at least 60-70 lbs since I saw her last though.
7 years