It's pretty hard to know that when you are only in your teens and may not have been exposed to a lot of different things yet. My view on it these days is pick a major in something that interests you, and ideally will provide you with a good living when you graduate. You can change careers later on, switch to a more fulfilling job that doesn't pay as well, etc. Its a lot harder to switch into something more technical/ demanding later in life; much easier to downshift instead.
There are also some other factors at play. Some types of jobs dry up over time. Most of the mechanical engineers I know migrated over to computer-related jobs over the years as opportunism for mechanical engineers (with the exception of those in building design) diminished. This is especially true for those who focused in the automotive section. Another example is environmental engineer; it was billed as the next great career. Large amounts of Civil students focused on environmental. And the market got oversaturated. Many who had dreams/ goals of helping to change/ improve the world found it hard to get jobs and had to move into other types of jobs that they were not very well qualified for.
After 30+ years of being an engineer I can't say this would be for everyone to do for a lifelong career. But it enables my family to live a good life, and 5+ years ago my wife was able to leave the corporate world and switch to a low-paying job that is more fulfilling for her. We would not both be able to do this without selling everything and moving far from urban areas. I suck it up (and can, since I have the education. degree and experience) so she's able to do better things. It works, and I occasionally get to feel like I am saving the world at times as well