I'll list the stuff I miss.
Sleep, sex, my body (my post baby tummy is just horrible, and I wish I didn't care but I do), lie ins, lazy brunches, Sundays out wandering with DP, DP in general as I hardly ever get time alone with him now. Reading, writing, not having to plan my life around naps and bedtime (my DS won't sleep in the sling, car or buggy), taking my time cooking at the weekend, baking, watching crap TV uninterrupted, lying on my bed drinking tea and reading my cookbooks, money to spend on myself, dinners and drinks out...I could go on and on.
But I tell you mostly what I've struggled with is the sheer weariness of complete responsibility for another person 24 hours a day 7 days a week. Some of the stuff I've listed above will probably improve as DS gets older but that responsibility won't ever lift. I'm an anxious person and having a child had introduced yet more anxiety - is he ok, will something bad happen to him etc etc
I adore my son. I love his little sounds and his little cuddles and the thought of something happening to him makes me feel...I can't even describe it it's so awful. But to claim all that makes up for everything I've lost isn't quite a true statement for me.
I don't want another child for this reason.