You're taking a big step, maybe spending a lot of money, and definitely spending a lot of time learning web development. You might be taking time away from family. You have to cut back on other expenses to fit this new direction into your budget. You're taking a personal risk, too, because learning something new and trying to become something better always makes you vulnerable.
You have questions, doubts. If you don't yet, they will come.
Is all this worth it? Is it worth the investment? What if you fail and people see that you couldn't cut it? What if you learn it all and don't like the life of a web developer or your job prospects aren't what you thought they'd be? Am I even capable of becoming a web developer?
