That's all right, Ann. I hadn't had my coffee when I wrote that post.
But it's true in any language: gwybodaeth ychydig yn beth peryglus
I hope the rest of the post wasn't as haphazard but it may well be.
Yes, the saying, in English, is indeed "a little learning". I was thinking in Swedish.
http://xref.w3dictionary.org/index.php?fl=sv&id=22