It’s having your view expanded logarithmically and at the same time focused into a narrow searing laser on what’s important. It’s both suddenly understanding things once unfathomable and completely not being able to conceive how I could have conceived certain notions pre-kids. It’s like the scene from Tron when the main character is hit by a bright white laser and he is instantly taken apart, dematerialized bit by bit and then put back together and everything has changed; he is and is not himself at the same time.
Its having your head turned inside out and you are no longer in an echo chamber of your thoughts about yourself. I don’t know what the opposite of solipsism is but it’s like that. It’s suddenly having your egocentric, heliocentric view ruptured and now wrenched around these tiny, little things that think for themselves but are utterly and devastatingly dependent on you.