Why is a video not showing up in my watch history?

This is a youtube question. it’s a trivial problem but i really love to know the answer.. Why does a video sometimes not show in the watch history?

i even made a comment on it and the video shows in the comments history but as for the watch history it doesn’t show…

ooops! these are 2 separate pictures why is it showing them as one?? (one more dang error😡) I just want to know HOW these things happen.. I mean i had to go in and fix my Music app library because it was showing multiple albums for ONE album… 😡😡 WHY DO THES THINGS HAPPEN??? 😖😩😫

UPDATE: here’s the OTHER picture since…for some reason it just did not post..WHATS GOING ON??😩😩