One particular nuance of the Java String that people new to Java sometimes don't fully appreciate is that a literal String is already a String object.

String literals, which are typically descriptive titles and messages, are output to the screen or printer as written. Depending on the programming language, ...

VBA will use strLastName as a literal string and continue. If you were searching the LastName field, the query would return no records (as it’s unlikely to find a last name entry of strLastName).