Unless he was down for an emergency, like the first time they'd had to rescue Ned, John's routine after returning home was set: into the villa, straight to his room, uniform off and into the bathtub to soak in water as hot as he could stand and as submerged as he could get while still able to breathe. When he'd soaked for as long as he needed to, he'd dry off and lie on the bed for a while with the lights dimmed and a window cracked open to let the sounds and smells of outside in, proverbially 'soaking' in sensation and gravity until he felt ready to emerge.
Down for a conference that he'd been cajoled into by Penelope (she'd been accurate on the description this time and he'd checked) he'd gotten to the 'lie on the bed part' and was calculating if he could get away with wearing his normal outfit to the conference, not a suit, when the phone on his bedside table chimed for attention.
"John?" EOS' hologram popped up as her voice issued from the device. "What is the meaning of this ritual when you go to the Island?"
"Hm?" John looked over. "What do you mean?"
"Your pattern of behaviour before going out to join your family." She clarified. "Virgil claimed it was to 'wash the stardust off' and refused to elaborate."
"You asked Virgil about what I do before asking me?" He asked, rolling over to face EOS' hologram.
"I have observed that humans can be staggeringly ignorant of their own behaviours and thought the observations of your medic may be insightful." Was her reply, sounding slightly miffed that her approach hadn't produced the expected information.
"Well… he did tell you, but he explained it the way he understands it. You know Virgil's mind works differently to mine." John started, frowning as he pulled together the words to explain it in terms that were meaningful to EOS. "It helps me to 'soft reboot' from Space settings into Earth settings." He explained. "I know it's a little tricky to understand but Five is a low sensory zone, there isn't much up there to smell or hear or feel, and it's a controlled environment. I adapt to that and my body turns up the sensitivity to compensate, for lack of a better word. Down here I'm suddenly surrounded with all the smells, the noise, the temperature variations and humidity. I've found it can quickly get overwhelming if I don't do something to mentally and physically delineate the transition point and tell my body it's time to switch settings and ease into it, since we can't manually turn down our sensor feeds."
He could almost hear EOS' processors whirr as she considered his explanation. "...humans are peculiar creatures." She finally declared.
John chuckled fondly. "All part of the human condition. Would you have us any other way?" He asked, sitting up to get dressed.
"I would not have you any other way." Was her fond reply.