I started lessons when I was 40. Never had a car in the family so I was a complete newbie. It was the best thing I ever did. Like PPs have said, it's the freedom. No relying on public transport, last bus / train home, arms hanging out of sockets with heavy shopping.
Choose your instructor wisely. Mine was fabulous. Very professional, and knowledgeable. Quite 'strict', i.e. do things properly until they are second nature, and he could TEACH. Not everyone can. Lessons are expensive whether you get a good instructor or a duff one (and there are plenty of those). Maybe contact your local Institute of Advanced Motorists for a recommendation. I took 2-4 lessons a week, and I didn't have a car to practise in between times, so just the lessons.
One thing to avoid perhaps is the 'how many lessons do I need' state of mind. I know they're expensive but I took the view that I'd have as many as I needed to be able to drive safely. There's no other area e.g. swimming, learning a language / instrument where people say "oh, you need 20 lessons, or one lesson for every year of your life, and then you'll be able to swim, speak French or whatever."
A couple of other thoughts that I remember having:
Re cost: It's expensive, but it's not going to get any cheaper.
Re scariness: First, look at all the morons who can hardly steer a supermarket trolley. They can (or can't!) drive, so surely I can. Driving isn't a supernatural power. It's about working a machine: doing things with your hands and eyes and brain at the same time. Like knitting/ sewing, or working a sewing machine or icing a cake. Hard and clunky at first, but it gets easier and that side of things then becomes automatic. Your brain learns and then you don't have to think about it and you can give all your attention to what's going on outside the vehicle. That's about learning to observe and interpret what's going around you - back, front and sides. Mirrors are your friend - use them until they wear out!
It's a set of rules, i.e. working the car and the Highway Code. And then add the unpredictable human side: other road users, pedestrians and their 'behaviour'; time of day (school /pub chucking out time) and so on. You unconsciously 'read' and anticipate situations all the time as a pedestrian. When you're driving, you learn to do the same.
Last pearl of wisdom (sorry to go on!)...passing the test is just the beginning. That's when the real learning starts!
Go for it - it's great fun!