Alpha decay is basically where you have a big friend group who decide they don't like four members of the group anymore and kick them out
Alternatively, alpha decay is when you have a big group who decide four members are sus and have them voted out
Nuclear fission is basically when you have a friend group and a new person joins but half of the group hates the new person and everyone takes sides. And three members are like "well heck this" and leave at high velocity
Nuclear fusion is basically trying to force two friend groups who hate each other to get along