I'm just making this thread out of curiosity. It's not intended as a problem-solving and advice thread by default, more of a "let's chat about art" thread, but of course everyone is more than welcome to ask for advice here. I'm saying this because sometimes when I poke fun at myself some people perceive it as complaining and it's really not intended as that.
With that said, I'm curious - are there any things that aren't generally seen as a Difficult Thing To Draw(TM) like hands and foreshortened action poses, but that you struggle to draw?
For me it's simple short haircuts, especially for men. I know how to do them in theory. I also get pretty close to people's heads at work and have picked up a habit of observing their haircuts for art purposes. And yet ... somehow when I try to draw a man with short hair my brain goes blank and it looks like I've never drawn hair in my entire life. I'm usually not the worst at winging something without reference, but somehow when it comes to short hair my brain loses all of its visual memory. It doesn't help that long hair just looks so much nicer on all genders and it's so much more fun to draw and I love GNC characters and besides, making their hair a little longer would suit their personality and the setting a lot better anyway and ... you get the picture. Pretty much all of my important characters that used to have short(ish) hair have a bisexual bob now. 
I know I just need to actually practise this but damn, it's hard to ignore my love for the bisexual bob. XD
What about you? I'm curious. 