Why do people smoke/vape

I started smoking when I was 12 cause I thought it was cool. I stopped for a while but I was waiting on the bus and wanted something to do so I picked it up again and then switched to vaping so I don't smell bad. I stopped vaping cause I came to the conclusion that it was gay. im on zyns now to stop smoking/vaping. it's really just a nicotine addiction. my eyes don't even feel fully open without it now. imma eventually stop this too. at least that's what I tell myself.