Humans seem a lot more familiar with the form of jogress where digicores are permanently fused than the kind I get to see a lot back at work. For simplicity’s sake, we’ll call it “convergent digivolution”. You know the crab cycle meme you guys post? It’s kind of like that…
Let’s say you’re an Agumon. You have a very close relationship with a Veemon. They could be your best friend, your sibling, your lover, your mentor, whatever. As long as you share a bond. When Digimon care for each other, we tend to have a lasting effect on one another. All that love’s gotta go somewhere: Right to the Digicore. And it lays dormant until it’s time to digivolve.
Basically, instead of looking like THIS:
A Jogress can look like THIS:
It’s all about leaving your mark on someone and letting them leave their mark on you. It’s some digimons’ life purpose, even. That’s how special that feeling is to us.