Did any of you guys at cool companies start somewhere subpar?

Im graduating soon. I spent most of college studying Math because I used to be an academia wannabe, and now Im starting my software career at a company in the finance sector which I believe is far below what my ability will be a year from now (I've been programming and reading CS textbooks all the time for about half a year and I'm getting waay waay better than I was when I accepted the job last semester). Im a bit concerned that it will be hard for me to move on though due to my lacklustre initial placement, and my lack of connections at competitive companies.

Did any of you guys start at a sucky company and move on to something cool?