I am having difficulty tracking down your exact quote, but I wonder if you are not refering to the moment in chapter two when Katnis volunteers to replace her sister as the female competitor for the Hunger Games. Note what the text tells us after Katniss goes up to the stage to receive the dubious honour:
I put my hands behind my back and stare into the distance. I can see the hills I climbed this morning with Gale. For a moment, I yearn for something... the idea of us leaving the district... making our way into the woods...
The irony of this passage lies in the fact that that very morning, Gale had suggested to Katniss that they lived together in the freedom of the woods to escape the tyranny of their lives. However, of course, now it is too late as Katniss will represent District Twelve and there is no escape. I hope this relates to the quote you meant. If you can tell me in which chapter it is, I might be able to respond more precisely, but I think it probably relates to the irony I have explained.