My kitten and his 'kneading'!?

When I first got my kitten he was 4 months old, hes now coming up for 6 months. The day he arrived I put down a blanket on the sofa for him and cuddled him in it when he came and sat by me. He then started 'kneading' on this blanket and I guessed it was a comfort thing. He doesnt do it anymore, only when I get the blanket out. Do you think he only 'kneads' on this particular blanket because it reminds him of his mum? or to show his comfort where he is now? Does anyone elses kitten/cat do this?