1). YOU HAVE TO BE FRIENDS WITH EVERYONE!
Nothing can be further from the truth. Networking is cool and all, but if you're networking with people who are incompetent and/or treat this industry as a hobby or side gig, then you're wasting your time. Think about it this way: you have a finite rolodex. That way you'll be very selective about who goes in it.
2). YOU HAVE TO PUT UP WITH SHIT TO MAKE IT!
That's what I was told as a PA on an indie film set. I quit the next day! Treating people like shit because it's an industry "ritual" is just not going to work for me. It's absolutely ludicrous. You can be firm and professional and people will respect you. There is no need to scream at people and push them around. If the person is incompetent, then fire them in a professional manner, and avoid making the same mistake twice. Simple!
3). YOU HAVE TO WORK HARD TO MAKE IT!
I've worked on pictures pulling 16-18 hour days. Am I exhausted afterwards? Yep! Do I get frustrated when I have to watch the director do a thirtieth take because he doesn't know what the hell he's doing? Yep! Do I have to deal with overpriced yet under-talented film school students? Yep! Even with all that, the term "hard work" rarely applies to this industry. I know kids that have to get up at the crack of dawn to work on farms, walk miles to get water for their families, and other HARD WORK! The film industry is mostly based on nepotism and who you know. I would never say it's based on hard work!
4). IT LOOKS EASY ENOUGH. I WANT TO DO IT!
Most people I come across want to be in the film industry for the wrong reasons. I love movies! I have ideas! I've always been told I look like an actor! It looks fun! Directing is common sense! And the bullshit responses go on and on. I usually want to end the conversation immediately after I get one of these responses, and this is why: this industry is not "easy." It's not hard work in the context of what I've stated above, but it's definitely not an easy path. This is one of the few industries where some of the most talented people are out of work. What does that say about your chances, newcomer? This is my advice to you; sit down and evaluate why a career in filmmaking is for you. Again, no bullshit responses! You can just as easily find countless other "easy" things to do, and you can watch countless movies. Look at that, you're still a part of the industry.
5). THIS IS THE PATH TO SUCCESS!
There is no "path" to success. There is no special road to follow. Some people start at the very top (usually with money and/or nepotism), and some people start at the very bottom (usually out of necessity). You can start in one area and end up in a different one. i.e. Going from the production side to the distribution side. You can start as a production assistant or a studio executive. Again, there is no path to success in this industry. Be your own navigator, and chart your own path.