Here's my take on it. During my tenure, I've worked with 2 kinds of cooks. One cooks because he/she absolutely loves cooking, creating, cleaning, hard work and high stress environments. The other only works in a kitchen because he/she needs a job, and may have some restaurant experience so that's their easiest go-to job. If you've been accepted to law school, you've obviously got a good head on your shoulders. But remember, if you choose a culinary career you will be underpaid, under-appreciated, overworked and you're going to get a few scars and callouses. If you attend culinary school, the debt will astound you, and it's going to be hard to pay off on the salary you'll make straight out of school. Down the road however, your degree may help to secure better jobs, but only after you've worked and had some experience. A close friend of mine recently went and got his degree from the CIA at age 53 after cooking for most of his life. According to him, he learned a few things, or at least new terms for things he already knew...and he's not better off than he was. Now he's just got another monthly bill to pay. I do understand what you mean; if you do something, you want to commit to it and charge at it 150%. That's respectable, but be sure you could really do it for the rest of your life before you have a 6-figure student loan debt.
So is 25 too old? H3ll no. Most employers look for experience solely. I once fired a 23-yr old Johnson & Wales graduate and hired a 55-yr old cook that'd never even graduated from community college. Best decision I ever made. The guy breaks his back for me and asks for more. He's on time, constantly cleans everything and doesn't complain when we get orders 10 minutes before closing time. The Johnson & Wales kid was fired after he threw a 12" french knife down the line because a server asked for an extra plate with an entree.
Work in the industry for a while before you decide on school. In a lot of cases, the work experience will be more beneficial to you. Read a lot of cookbooks, reach out and talk to chefs on this forum and others. Just learn, then make your decision.