How does Charlie feel toward Algernon before and after the operation?

Both before and immediately after the operation, Charlie sees Algernon as a competitior. Charlie thinks Algernon is a "pretty smart mouse" before his operation because the mouse can beat him by finding his way through a maze faster than Charlie. However, after the operation, Charlie is triumphant the first time he beats Algernon. His attitude changes, however, once he realizes the experiment on his brain will ultimately fail, as the experiment failed with Algernon. He then begins to sympathize with the mouse because they ultimately both share the same fate.