There are two things that you need to understand when thinking about moving. One of these is to do with the type of income that you have at present and what type of income will you have in the future. If you are someone who works full time in the same field for an employer, this will change the income equation dramatically. If you have a second job and you think that your income could rise in the future, this can actually reduce the amount of tax that you need to pay.
Income from past jobs can also be used for tax deduction purposes. If your income from your first job was more than what you have now, this could be used to offset your current income. The IRS is not sure if you will have enough money in the future to support yourself. In other words, this does not mean that you should give up your current income to take a tax credit. You need to look at your situation objectively, and decide whether or not you should take this credit. If you do, then it should reduce your taxable income significantly and can give you a tax break that is worthwhile.
The second thing you need to know is to think about your future income. This means that you need to look at what you will have when you retire from your current job and what you will have when you move into a new career. If you currently make more than you need to earn on your current job, this can be used to offset the new salary that you will get in the new position. If you currently make less than you need to make on your current job, this can be used to offset the new salary that you would get in the new position. Whatever the case may be, you must determine whether or not this will reduce your taxable income. If it will, you might want to take this as a tax credit to offset your current income.