The struggles! The frustration! The turmoil of training in something like a CrossFit gym is the constant grind of having to work on things that you think you "suck" at. You don't suck, you're doing something that is hard and actually worthwhile, you're doing a style of training that when you finally get it you'll have something to show for it. Whether that be "Hey, watch me do handstands!" or "Hey, check out my snatch!". No one can deny that if you show someone that has never seen Olympic lifting before a video of you doing a snatch they are both stupidly impressed and terrified for your safety, and that's cool.
CrossFit works, there is no two ways about it, I've seen people go from not even being able to hold themselves on Olympic Rings to doing muscle ups, I've seen women struggling to swing a 12kg kettlebell develop a 100kg deadlift over no time at all, and the nice thing about these "skills" is that your physique will just change out of a result of the things you have to practice to do such things.
Accepting what you're strengths are and maintaining them is very important, but, in order for you to progress in your own development you need to attack the areas you haven't delved into before - if you feel comfortable in your training you should be wary. Every workout you do should be attacked with maximum intensity, how often do you leave the gym thinking "How the hell did I just do that!?" It's pushing through that mental barrier that really gets results and it is what will set you aside from someone that just attends a class.
We all have movements that we struggle with and every time they come up on the whiteboard you wonder if you can just sneak out the back door and go home, but it's those horrible moments that if you approach them in the right way you can prevail and become stronger! Think double unders, how many sessions of whipping yourself silly does it take to start being able to do single double single double? Yes it's frustrating but how good is it when you finally start getting some consistency to it? SOOOO good! And it's only through your hard work you can get that feeling!
Always discuss with your trainer if there is a movement you are struggling with, they have an encyclopaedia of progressions for you to work with and yes some of them may seem dead simple and you may feel like you're in the beginners class again, but if that's what your trainer says you need then just go with it, persistence will pay off and you'll be on your path of working your way up through the scaling to the full motion.
Taking an interest of what you're doing outside of the gym is stupidly beneficial also, watch any videos from CrossFit.com, or any official weightlifting videos, gymnastics competitions etc. Not only will you feel motivated, but watching someone do something repeatedly makes mimicking so much easier, having a better understanding of what you're doing will always increase your performance. Just remember if you come across a new exercise you haven't seen before or program to ask your trainer before attempting! Some things that are out there are for professional full time athletes, the program isn't to fault but if you're working forty hours per week and have three kids chances are you don't get afternoon naps... Happy hunting! GO GET SOME!