It's just unfortunate that they are just so hard to debug. Take these two statements
Thanks to Tom in the forums for helping me see what I missed
For those with a strong, habitual PL/SQL background such as myself, I think making this mistake at one point was pretty much inevitable.
Basically the first one accepts to expressions within an OR statement, while the second concatenates the two strings as desired.
It makes me wonder how many times strange things like this happen with human language. I'm sure there are some good analogies out there.
I certainly don't envy those people constructing multi-lingual applications - not that much demand here down under :-)