I didn't downvote ya, but I'm sure those that did have a variety of reasons including:

1. This is not "funny". I'd say it'd fit better in "cute" or "aww" or maybe even "pics". Heck, there may be a half dozen other places it would fit better than funny.

2. The reason many people get upset with re-posts isn't simply because it's been here before, but because all it takes is a simple 10 second effort on the part of the poster to see this (and thus prevent the re-post). People are upset when people are lazy. Here's the results I got when I did a 10 second search here. . You can see this gif (or the youtube equivalent) gets re-posted several times each month.

Again, I agree that some people may need to relax a bit, but here's how I look at such things here:

To many, Reddit is like the local Piano Lounge on the outskirts of a Touristy town. This particular Piano Lounge has a jukebox that allows people to upload and share their own appropriate songs. The large crowd of regulars and locals take delight in sharing their unique finds ,broadening their horizons, and stroking their egos with their classy music. And every night, a small group of tourist walks into the lounge for the first time. They come in talking loudly, dressed oddly, and bumping into people as they make their way straight to the jukebox. And then they proceed to pick "Piano Man" by Billy Joel to play. They think it's a great song. They enjoy it. The group of people they walked in with enjoy it and think it's the most clever thing ever (Piano Man playing in a Piano Bar? How awesome!). They laugh loudly, sing along, and then stumble out into the night never to be seen again. But not before pumping $5 more into the jukebox and selecting Piano Man to repeat 5 more times. Clearly, the regulars don't find this as entertaining. And because of this, there are signs hanging above the jukebox and posted all around the Lounge. They say "please check before picking a song to play"

TL;DR: Don't be a tourist. :)