Oh dear

You make me grin with your post. Let me guess, you're new to the industry right or a fresh graduate and I think you are a guy? Enthusiasm is always good - trust me, you'll be meeting lots of fake smiles around with enthusiasm you'll do fine.
Having worked with 3 airlines so far, I was also like that, many of us came in with full of enthusiam, energy and drive, but you have to remember that it's going to be completely different from what you actually perceive the job to actually be!
I really discourage people who are not really keen or have any real waitress or F & B experience to apply. You have to remember that this job isn't glamour - Blame it on all the media hype.
This job is political - Simple reason, most cabin crew have too much free time during layovers and gossip spread fast - Really really fast. For example, if you offended someone unintentionally - you end up labelled, word spreads quickly and presto, you're "marked". I know of cases where someone didn't like a particular crew and they waited for her to make a major mistake and BOOM!
To be frank, this job is basically a waitress - high class to a certain extent, with some safety training, some F & B training, PR, deportment, but don't think it's a "PROFESSIONAL" career. Please. If you have like a solid credentials, you are probably going to regret it sooner or later.
Politics for the cabin crew line is different from the office. You'll know what I mean when you start flying. You swallow your pride fast. I swallowed it quickly. You have to and you'll survive.
This job isn't about "travelling" - This is the number one most passe answer we hear from candidates - "I want to travel" - LOL, I remember one recruitment officer slammed with "You could buy a ticket and travel for the same thing right" - Some layvoers are short, you reach destination,exhausted and you sleep like crazy, wake up and then new flight - depends on the airline. You may get a chance to sightsee and stuff.
Been flying with 3 airlines so basically, it's the same, it's more intense in certain airlines - depends on the culture. Some airlines tend to be more political as a lot of bitches want to be "Noticed" as I'm the best!
Obviously, if you screw up big time don't expect people to come to your rescue. Don't think "Ooooh, I'm new" - Some will help you, some will let you die. You swallow your pride, cry if you have to and do it.
But there are positives - I have good friends from a very select crowd - Most are fake plastic bitches, I learned how to walk properly and graceful, smile on cue and laugh on cue at every stupid remark, you basically transform into a "Swan". It's an experience, you will change - trust me!
Good luck to everyone!