It will never be easier or safer for you to start a startup. In five years, you might have a family to support (not necessarily so, but odds aren't against it), and the decision becomes remarkably harder to make when your own needs aren't the only ones to think of. That "one year" of savings will last a month or two if you have kids.
There are many businesses that are recession-proof, and many that can still pay you a salary during a downturn, though your current job isn't necessarily in one of those businesses (and your startup might not be in one of those businesses either). Without a lot of experience, it may not be immediately obvious to you what businesses will weather the recession well and which will run into trouble.
Having a job now does not mean you'll have a job in six months if the recession hits hard. Don't imagine that your job is permanent if things go badly for your current employer. There are no guarantees in anything. At least with a startup, assuming you build something people want, you'll have something people want in your possession rather than just a last paycheck.
That said, I'll tell you what I wish I'd known at 23: Have fun. Do exactly what you most want to do. If that is starting a company, traveling the world, starting a band, writing a novel, getting another degree, or some combination of these things, do it. You will never be in a better position to do exactly what you want to do.
Your mother worries about you, and thinks about basic needs first. You live in a time and society in which basic needs are all but automatic: you can work two days a week at a crap job and make a subsistence living as long as you're single and live frugally. You can always get a crap job if you need it later. Since you're college educated and presumably a nerd, you're even better placed...contract work pays enough to get by on a few days a month.
As mixmax pointed out, the old saying that you won't regret the things you did but the things you didn't do is probably as true as any truism ever said. When you're 30 you'll begin to get a sense of this...I suspect that when you're 40 you'll have an absolute certainty of it (I'm not yet to 40, so I don't know for certain...but I passed 30 a few years ago, and it only seems more true each day).