If every feature of a programming language syntax can be used in about 100 kilobytes of code, and your project is 3000 kilobytes, that's a 30:1 "sameness ratio" at best. If you use every language feature in that program, any 3% (if not more) of your program will look the same as some other 3%.

Most programs don't exercise every language feature throughout most of their code, so their pieces look even more self-same than that.

In Lisp, we have to learn to factor in the identity of the operators into what is "same": learn not to see (defclass bear (animal) ..) as being the same "same" as (block foo (init) ...).

When you're reading Lisp code, you're seeing chunks like this:

    xxxxxx xxxxxxxxxxxxxxxxx
       xxxxxx xxx xxxxxxxxxxxxxxxx
              xxxxxxx xxxxxxxxxx
                xxxxxxxxxxxxxxxx
              xxxxxxxxxxxxxx
                xxxxxxxxxx
 

You have to train yourself to see the upper left corner of this blob before any other processing:

    (defun xxxxxxxxxxxxxxxxxx
       xxxxxx xxx xxxxxxxxxxxxxxxx
              xxxxxxx xxxxxxxxxx
                xxxxxxxxxxxxxxxx
              xxxxxxxxxxxxxx
                xxxxxxxxxx

The meaning of the rest of it depends on that one; it has to look different from other blobs that have something else in that corner.