system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Buddhism

I've read wiki but am still confused on what exactly they believe.
gpt
True ELI5: Buddhists believe you will be happy if you recognize that things you like will go away eventually.

It is likely that you are confused because there are hundreds of different schools of Buddhism, and there is very little in the way of a western-style dogma to preserve the history or authenticate cannon. The narrative below is the wildly abridged common origin story. 

Long version: The Buddha was very rich as a young man, but he was unhappy. He left his palace one day, hoping to find something to make him happy. On his trip out, he saw poverty, illness, and death for the first time- he had been totally sheltered from that before. He was even more sad than before. The last thing he saw on his trip was a holy man, who was happy- so the Buddha tried to find happiness for his spirit, too. 

After a long time and many different strategies, he sat down under a free, cleared his mind, and worked it out. It took a long time of sitting, but eventually he reached a thought that was so clear and compelling that it gave him happiness and he became enlightened. 

"Suffering is caused by attachment." Attachment to life, to things, to feelings and sensations- all of these things are transient and you will be sad A LOT if you act like they aren't. 

After that, it all goes wonky in the way of sectarian religions. The Tibetans have a pantheon of gods and demons, zen is split on whether you can achieve enlightenment through practice or spontaneously or at all, and there are any hundreds of other differences.