A colleague at uni, in 2017. He told me about it, and mostly recommended me to listen to videos from A. Antonopoulos. He quickly made me realize that my little sidestep into XRP during the 2017 bull run was a padawan's mistake from someone who didn't see the big picture. I then completely switched to Bitcoin in 2018. Went to a LN hackathon and was hooked ever since.

Actually, I did go to a Bitcoin meetup sometime before all that in 2016 in Seoul, but the speaker did not manage to convince me that it was anything else but magic internet money.

As a side note, my colleague almost got hired for a professor position on Blockchain and AI, but the position never ended up being created. But that colleague knew the technical ins and the outs of it all, and I owe my current fascination with it mostly to him.