I find a bunch of things on youtube, videos longer than 1 minute, that i add to "watch later" list, to well... watch later. Some things i watch the same day, some are there to stay.

Around 10-20% of the older videos are gone... from copyright infringements (music in video), to deleted channels, to "not available in your country). What I hate the most is, that even the video titles are removed, so i have no idea what's gone, just the "[Private video]" or "[Delted video]" in the list.