Chrome DevTools Performance Tab

The performance tab in the Chrome DevTools is an amazing tool that unfortunately a lot of web developers are not sufficiently familiar with. I resist attempts to push me to try to start optimizing it or tell the team how to optimize it before I get sufficient data and sometimes you know I get pushed hard and I push back because I know that if I start optimizing with insufficient data like I said either I'll optimize the wrong thing or maybe I'll optimized the right thing but I wouldn't know that I actually made any difference. If I'm not properly measuring the system how do I know that I'm actually improving things and not making things worse? So I assume all right there's no arguments we made so