lump.

The change in colour in your face when the person you get the most embarrassed around smiles at you.  The rush of emotion when your cat climbs onto your bed right after coming out of the litter box.  The paper towels you use to [unsuccessfully] get the strong pine scent off your bedsheets afterwards.  The change in facial expression when you walk out of the bathroom trying to tuck your shirt in and someone walks by.  The struggle to get your headphones on when you're close to walking past a person you have no earthly desires in heaven or hell to talk to.  The great clash of cymbals within your brain when you walk down the hotel hallway and a hunky man walks behind you for a number of minutes and you try to lose him in the laundry room and end up talking about Jesus with one of the cleaning staff until one in the morning.  The horrid taste in your mouth when you can't find the courage to talk about Jesus with anyone.  The elation when you find out you can open your eyes underwater.

All, leading to a lump in the throat.