Working Girl Dilemma

Good Morning little Bloggie. Today I am a little down in the dumps. I'm pretty sure it has to do with the company party I attended this past Friday. I have been working for my company for 2.5 years now so I am comfortable and happy with my job and co-workers for the most part.
At the party I was introduced to one of my clients for the first time, and I was truly excited to meet them after all this time. Once I was introuduced, one of the first things they said to me is "we have to admit, we told your boss we didn't think you were going to make it for a long time but now you've got it and girl you kick ass!" Although it is a compliment to my current work, it still hurts that they thought this and communitcated it with my bosses. I take great pride in my work and really do the best I can so when I hear that the best I can isn't near good enough, it just feels like a slap in the face. When I first started working there, they gave me a HUGE workload full of their most high maintenance clients and more than anyone else (they must have had a lot of faith in me) but it really affected the attention I was able to give each of my clients individually. I know that is what happened but they don't know that part of the story.
So, I'm not sure where to take it from here. I know that I am going to continue to do the best that I can and even try a little harder. I am also going to try to not think about what was said because it doesn't do any good to beat myself up over it. The good news is, in their opinion is that I "kick ass"...so whatever.