I heard it back in 2011 where in there was a huge hype of mining Bitcoin using GPU's and there were numerous facebook groups where they posted they rigs and also had many tutorials for other to follow or even customize their rigs in order to work better.
I heard it few years ago when the price of bitcoin is not yet high. In addition to that, when I heard it im so curious because I do not have any idea about bitcoin so that I try to conduct some study about it. When the time I know what bitcoin is I start to use it properly and as of now I still use it.