I got into anime in 2001, with Cardcaptor Sakura among the first shows I watched. It quite directly led to me watching Sailor Moon, then Utena.
These were popular shows and they all had yuri elements. It seemed reasonable to think this would be the tip of a less mainstream iceberg. My expectation was effectively that yuri would be somewhat easy to find in shoujo manga, and that it would go further than was seen in anime like Utena.
I tried to look for it. This would have been in 2002. It turned out that yuri in shoujo manga was hard to find, thin on the ground. Looking for yuri manga mostly turned up ero doujinshi, but even those were far from common.
In hindsight, the iceberg was BL.