I am currently building my website from scratch. I have never done that before and I am wondering if I should optimize my website for the phone.

I want to build a late 90's inspired website (they were not optimized for the phone back then) but since so many people got smartphones these days (with some people only browsing the web on the phone and not on a PC at all), I am concerned if I would be missing out a great deal of visitors for my site if I choose not to optimize it for the phone.

Should I optimize (and in the process, my website will lose its late 90's charm) or not optimize? Do you think all websites should be optimized for the phone?