I don't really miss any specific time periods or events in my life because, even if I was doing something that was objectively "fun" or "good" or whatever, I've always had a hell of a time with myself as a baseline and then suffered from something or another on top of that, which basically snuffed out my ability to ever really be happy or truly enjoy anything at all to the point where I'd be able to look back fondly on it and miss it, due to the constant bullshit that was also going on personally and on the sidelines... if that makes sense.
I do wish I could still knit and crochet whilst lying in bed, though. It was quite soothing and gave me somewhat of a sense of accomplishment. I'm too sick to even do that anymore.