Seaming and weaving in yarn ends are my least favorite parts of knitting. It always takes me by surprise how long those things really take.
When you bind that last stitch off your needles it feels like you're done, that's it, it's finished. But no. There's still the blocking, the seaming, the buttons and all the other finishing touches left to be done.
With this cardigan it took me an extra evening of work to get everything ready. I never seem to remember how slow work seaming is (especially if you don't really do any other sewing like me and if you want the resut to look neat.) and I get frustrated when I'm not finished by the time I thought I would. I always seem to underestimate the time it takes thinking "oh it's just a couple of seams and a few yarn ends + 6 buttons, that should be a piece of cake!" But when you are already into your third hour of sewing and your sleeves are still completely separate entities from the body you have to admit the whole thing starts to suck. Big time.
Luckily it's usually all forgotten by the time you get to wear that lovely new cardigan the first time.