I've been in the airline industry for nearly twenty years.
Here's my 2c, and the only part you really need to understand: The two people who's lives I value the most, above all others (my children) have been given the following STRONGLY worded advice on a career in airlines: NO. DON'T DO IT.
Enough has been said why in the thread, but I'll add my own little part: The sheer randomness of the career. People will tell you it's about effort and being proactive. Not in my experience. That's basically a given. Everybody who's made it has put in a lot of effort. Yet the career is still utterly random. When asked where a prospective candidate for employement sees themselves in an interview in other careers, the candidate may well be able to give a coherent, logical response on career progression. As a pilot? Well, in my experience the best answer you can give is "Employed. Hopefully as a pilot." The cyclical nature of the industry, medical requirements etc. meansyou could be out on the street at any time. It is BRUTAL on family and social life. Hobbies etc, things that you need fixed times for.......gone. People who didn't do this job, then whine about how pilots act like 'spoiled brats'.....well, you didn't do it. You simply don't know what you're talking about. And don't bring up some random example of one of the epicly good jobs in aviation, 99% will not get there, and it has little to do with lack of effort on their part, as I said, that is a given.
It's a great job - and a terrible career.