I think they can become more aware of certain sensory issues as they become older. As Al1son said, for ds, its like he can't quite get his head around what the problem is, but knows somethign is bothering him then eventually manages to narrow it down and identify the source of the problem.
Ds has recently started refusing to wear a particular coat. Typically its his winter coat - he now only wants to wear his lightweight summer rain jacket. I initially thought he was just acting up, as he wore it last year with seemingly no problems.
After weeks of battling with him to put it on for school, he finally managed to tell me that he hates it because the cuffs are always wet. 
I was really puzzled by that one, but then I went and had a look at it, felt the cuffs etc and realised that the knitted cuffs get very cold, as the coat is hung on a peg which is against an outside wall of our house overnight. I now either hang it on the radiator by the cuffs or tumble it for 5 minutes before he has to put it on.
Ironically, I bought that coat specifically for the knitted cuffs, as he prefers to only wear trousers with soft stretchy waistbands, so I thought he'd prefer it. 
He has also started shaking his head a lot and when I asked why, he said his hair keeps going in his eyes and tickling his face. He does have long hair - his choice (surfer stylee) but I have only just trimmed his fringe and its nowhere near his eyes. I have suggested that having a new haircut would be a better option than constantly shaking his head, but no dice apparently. Having watched him, I think the real problem is him catching sight out of his long hair out of the corner of his eye and reacting to it as if its touching him.
This week he has been head shaking, vocally stimming (throat clearing) and screwing up his face a lot, so I am assuming there's something up, but we haven't got to the bottom of it yet.
He seems to suddenly have become more self aware in several areas. He told the EP last week that he knows what the facial expressions and body language of other people are when they are feeling different things, but he can't see it in them when its happening so he struggles to know what other people are thinking/feeling. He's just coming up for 9 years old and is definitely starting to notice more about himself. This is great when it means he can articulate a problem and we can help, but not so great that he has started to notice how different he is to his peers.