I wish people paid more attention to this scene when they accuse Walker of taking the serum for power hungry reasons to get fame and glory when we see him once again visibly uncomfortable with the attention. He puts on a public face front when the people are wanting his autograph but as soon as they are gone, his face changes and he’s got his hand in his face in exhaustion. He’s not there for the celebrity of it all, he just wants to do the job and he wants to do it well, a sentiment echoed by his words in Episode 2 in the locker room. And he takes the serum because he thinks it’s the only he can do his job well and not let anyone down, and as Lemar reminded him, think of all the lives he could have saved if he had the serum. He was driven by a desire to do his job well, make people proud, and protect people, not because he wanted to seek power to simply be powerful and cool and famous.