It maybe a mistake, but don't think much about it. It's kinda useless if you think about abandoning what you are supposed to do with what you already got.
Make something out of it, this Mechanical Engineering thing. You can still fantasize to mecha without compromising your job, right? I mean, I'm with a crewmate now whose job is to fix electrical stuff, but then he also customized his old van and upgraded its engine. He's an electronics and comm engineer, by the way.
Passion. It's what drives you to fulfill your dreams whatever conditions you may face.