Why does SNO -BOL toilet cleaner taste so sour?

i tried SNO-BOL toilet bowl cleaner (put a small bit of it on my tongue), it contains hydrochloric acid btw. it was SO sour it was unbelievable, it was like placing 1000 warhead candies in my mouth at once , or biting into a trillion lemons. it stung it was so sour. it was even more sour than Lime-X cleaner and Lemishine, it was more sour than the sourest candies as well. i mean it was so sour,