I dont get this youtube crap?

I love this video i put on youtube. when i clicked on my channel it played. then i uploaded a new one and it took the other video's place. so when you play it the newer one would play instead. i am just wondering how to change your video so when someone clicks on your channel it plays that video first.I dont get this youtube crap?
OK

at the top of your channel page(above your video but below the search bar) click on ';Videos and Playlists';

on the right side you should see ';featured layout'; ';featured content set'; and ';featured video';

click on ';featured video';

now select the video you want

and click ';save changes';