Same here - I did not start to really notice differences in either my appearance nor how I felt until about 55 or 60 pounds were gone. Then, it was like a switch flipped - I suddenly felt more energetic and wanted to move around more - I became the sort of person who bounds up the stairs two at a time.
At 75 pounds, another switch flipped - my appearance changed very quickly, and other people started commenting on it.
The good news is, the more you lose, the more those small differences matter. Think of it this way - when you are at your biggest, the relative change is smaller. The more you lose, the greater a difference each 5 or 10 pounds makes. Search the forum for "paper towel theory" to find a number of posts quoting an insightful essay on this topic.
High weight: 275 (August 2009) *** Low weight: 155 (October 2012)
Today, working off a partial regain. Current weight: 196.
* Make the best choice I can make, with every choice.
* Remember that the temptation in front of me is not the last of its kind that I will ever see; say "I'll pass today."
* Say "no!" to my whiny inner five-year-old.