1. You need to already be in great shape to start CrossFit
The scalability of CrossFit is one of it's most important foundations, and it should be thoroughly explained to beginning Crossfitters and people interested in starting CrossFit. You don't need an extensive athletic background or a deep knowledge of Olympic lifts, gymnastics skills, or crazy endurance. The only thing that someone needs to start is a desire to put in the work to improve their health and fitness.
2. You're guaranteed to get hurt
A common attack against CrossFit has been that it leads to a very high number of injuries among participants. Like any sport (yes CrossFit is a sport) there are going to injuries, and with CrossFit being a very physical sport athletes unfortunately do find themselves hurt from time to time. However there has been no conclusive evidence that indicates CrossFit causes more injuries than running, cycling, football, soccer, softball, or any other sport. In order to minimize the risk of injury you should always listen to your body and give yourself the time to rest and heal so that you can stay healthy enough to keep training.
3. If I'm a girl it will make me big and bulky
This is a big myth that many people outside of CrossFit seem to believe but actually holds no weight (pun intended). Without ever entering a regular CrossFit box and seeing the wide range of women who do CrossFit, their idea of a female CrossFitter is shaped by what they may see online or on social media. The bodies of the elite Crossfitters do get most of the visibility on these platforms, but in reality they make up a very small minority of women who actually are doing CrossFit, and their body types are by no means the norm for female Crossfitters.
4. Everyone only eats Paleo
Sure a lot of Crossfitters choose to follow a diet of some sort, and the Paleo diet seems to be the most common, but this doesn't mean that it's a necessary part of doing CrossFit. You won't be shunned for eating those grains or cheese. Everyone's body is different and what's most important for each athlete is that they find a nutrition plan that keeps them healthy, supports their work in the gym, and most importantly makes them happy.
5. You have to compete with everyone else
Competition is a part of CrossFit, but it's 100% up to each athlete how much they want it to be a part of their CrossFit experience. Some people thrive on the competitive nature of CrossFit, and going head to head with other box members keeps things fun and provides motivation to push hard during each WOD. On the other hand some Crossfitters much rather keep the competition to a minimum and the spotlight off of them by just competing against themselves. Just remember it's always up to you how and when you want to be competitive.