<human>: This actually happened last weekend but i didn't realise until today when I was going through my stuff...

So last week I was applying for a business/commerce graduate job that required a cover letter along with academic transcript and resume. My academic marks are nothing spectacular and i was basically relying on my cover letter and work experience to hopefully get an interview. 

Then i saw what i wrote last week which was "return OF investment" instead of "return ON investment". So now i sound like an idiot who doesn't know shit to do with business and i can't even resend my cover letter since the deadline was last Friday. 

So basically, i fucked up...hard and most likely will not even get a reply from the firm which i really wanted to work for. I know i sound silly at the moment and it may seem like a small thing to certain people. However, this position i want is very competitive and i may have ruined any chances i have because i didn't pick up on it during my proofreading time.

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: didn't proof read properly for grad application cover letter, hate myself and possibly be fucked once i am graduated from uni