How can we make stupid Acrobat Reader find strings with spaces?

If I want to find the string " nul" (with a leading space), that initial space is ignored by the FIND function of AR and is treated as "nul", The same happens if I want to find something like "nul " (with a trailing space).

If I want to find something like "nul nul" (with a middle space), it works properly.

How has nobody noticed that yet?