alright thinking about it, it doesn't add up...
simply because he reaction to seeing his hand when in the cell with leech was as if he hadn't seen it for a few decades, you couldn't put into words what it would be like for him to notice that again.
however if his transformation had only happened a few months prior then one wouldn't react that way, even rogue who is unable to touch people didn't overreact when she touched bobby for the first time, she didn't jump on him or kiss him, possibly because the mutation hadn't affected her for a long period of time, couple of years max.
if beast had only turned blue relatively recently, then his reaction to being around leech wouldn't had been anything near as euphoric as it was.