I quit caffeine about 8 years, only having a white tea on occasions. But I love a cup of decaf every so often. One day at work, one of my coworkers swapped the decaf pot with the regular pot and I drank a 16oz mug before I realized what was going on.

I was absolutely lit up and it was an incredible experience. I felt utterly amazing. Like I could take on the world. I had a hard time focusing at work, because I just wanted to be talking to people (not an extrovert) or going for a 10 mile run.

I can't compare it to cocaine, because I've never tried it, but I'm guessing the reason for your perception of it is because of your tolerance to caffeine.