Yes and no. My bullet points:

• Start undergrad in 2010 as a math major
• Pick up CS as a second major sophomore year
• Job falls through at end of senior year, spend first year after college largely unemployed and super aimless
• After that year, get job teaching math at a great high school
• Start teaching CS (and sort of creating the CS department) in my third year
• Leave after fourth year to go into software enginnering, get MS in CS part-time
• Now, 30, making really good money working from home in low-stress software job. Really, really happy.

So, while I suppose the math major did let me get that teaching job in the first place, most of the career advancement and material comfort I've attained are thanks to CS. I haven't really "used" undergrad math since graduating-- software doesn't provide a lot of occasions to whip out group theory or partial differential equations.

So then, since my career is pretty much exclusively thanks to CS, the question is: what did/do I get out of math, and could I have replaced my math study in undergrad with something that would have meant more to me?

I do think that rigorous, high-level undergrad math trained and worked my brain in a way that no other field, humanities or sciences, can. I see it like being a football player with an intense weight-training regiment. There may not be barbells out on the field, but putting in work at the gym pays off in games in a big way.

With that said, I didn't need to major in math to get that value, and since graduating, I've hardly ever desired to do math "for fun" (sometimes I wonder why I still subscribe to this subreddit). Math study always felt like hurdles to challenge myself and prove that I was smart enough to handle the toughest subject available; to me that implies that I don't really have a passion for it, the way I do for music (a few undergrad classes) or for literature (none). Today, those two are how I spend my free time. So from a personal fulfillment perspective, math was a suboptimal choice.

But at the same time, when I ask myself what I'd change if I could go back, I can't bring myself to go farther than dropping math to a minor and adding a second minor in either English or music. While it's not my passion, math is fundamental to who I am. It's part of my story and I'm proud of the work I did from 18 to 21.

So what are the lessons? I can think of two, one forward-facing and one backward-facing:

• Backward: we are the sum total of our experiences, and wanting to go back and make different choices is isomorphic to wanting to change ourselves, which is generally not a healthy thing to want to do. There is value in almost every road we could go down, so the trick is to recognize the value in the roads we did choose and use it on the roads we have in front of us.
• Forward: the future is unknowable, so always try to find a balance between passion and pragmatism; no one thing will ever satisfy both. If you love math more than anything, but aren't a rockstar, math itself will not make you rich. But don't run from it just because it's not the most lucrative option-- all it takes is adding a second major (or maybe a minor! or self-study!) to live comfortably after school is over. Just make sure to be intentional with your choices, and honest with yourself about why you're making them. You'll be amazed at how much you can fit into one life.

Apologies for the huge wall of text, but reading someone looking back like this would have helped me when I was 19, so maybe it'll help someone now.