This question comes up at some point or another with just about everyone who learns to drive. Most people ask it out of pure interest to see roughly how long the lessons would take.
Unfortunately, like most things, the answer is:
It depends...
According to the DSA, the 'average' driver takes 47 hours with an ADI, and 20 hours of private practice with a friend or family member.
Going from personal experience, this number can vary a huge amount. Previous knowledge from using other vehicles can drop the number of lessons to as few as 15-20, while difficulties can increase the number to 100+.
However a more accurate guide is 35-50.
Now that the hours are out of the way, on to the more important stuff...
The number of lessons it will take will vary, just like learning any other skill. Personally, I find learning a new language very hard, whereas others can pick it up fairly quickly and can learn to speak several different languages.
Something else to consider when comparing your experience to someone who took their test several years ago is that things have changed. Over the years, not only has the driving test become longer and more involved, but road and traffic conditions have got worse. More cars on the road, and more complex layouts make learning to drive harder than ever.
At the end of the day, everyone's different, but almost everyone can learn to drive a car safely, you just need to learn the right way.