When I was in high school, the most powerful computer money could buy was the Cray 2. The thing would require a room all by itself. I don’t know how much it sold for, but an old MIT article says that it cost $140 per central-processing unit hour. In other words, if you had to ask how much it cost, you could not afford it.
It provided 1.9 GFLOPS peak performance. It had 1 GB of memory.
In a recent iPhone, the GPU alone has more number crunching power than the Cray 2 had and just as much memory.
We can play a little thought experiment. What if I had gone to the Cray engineers and told them that, one day, I would be able to fit their entire computer in my pocket. What would they have said?
And what if, today, I were to tell you that in 40 years, we will be able to fit all the computational power of your phone into nanobots that can live in your blood stream?