I used wireshark every day for 10+ years supporting load balancers in customer networks. Between pcaps and core dumps, it was some of the most interesting data to work with. Learning libpcap and eventually writing my own version enabled me to pivot out of tech support for the product into development. I joined as a support engineer and left as a principal software engineer writing the code I was previously supporting. Wireshark and gdb let me teach myself so much, I never had to go to college.