You can’t run from who you are. Not your brain, not your inclinations, or your experience.
At the very least, you are a lost sock. He will look for you in various nooks and crannies for an indeterminate amount of time. He will wrack his brain, struggling to think of the last place he left you.
It will be a mild annoyance.
I know you had a brain tumor as a child, and I’m sorry for that. Now that I’m older, I recognize that a lot of your abilities and actions have been influenced by that incident.
Instead of doubting someone’s love, it is important to accept it, yet not rely on it.