Pony - this is a freakin' classic. I'm putting it in the Salt's thread.
(Dog, dude, you're way too uptight. Have a mimosa or something.)
Chicks won't stay with you.
There's no place to take a crap, or it's always a real pain to deal with (the head will leak, smell, squeal, clog, squirt, and finally crack off it's mount one romantic evening when when your 1st and only date's been swayed for a stay-over. Your holding tank will have already been choked full as the head breaks, and you've unknowingly managed to improperly set the Y valve, so the over-pressurized system is about to blow the crap out of everything). There's nowhere to take a real shower, let alone a hot one, because the bottom of your hot water heater (all 6 gallons of it) will have long since rusted away and the element is fried anyway.
Other reasons not to liveaboard are mold (a special kind of mold unique to your boat and you, a mold that will find it's way into the cheap plastic cups left aboard with little anchor decals and labels like 'captain' and '1st mate' on their faded blue or red finish. You will drink this mold and it will grow in you, causing odd rashes and an awful cough, especially if you smoke).
Still more reasons to avoid the small sailboat life are; damp clothes, $70 swollen history books with stained pages that you can never sell back to the cutthroat college book store, chainplate leaks that drain into your bling shoes, jerking dock lines will moan and keep you awake like a snoring fat wife, and a most inadequate desk (they like to call it a chart table) where everything on it's surface must be scrapped off in order to open it's lid.
You will most definitely smack your head several times a month, and the scabs on your swollen scalp will train you to duck after about the 3rd visit to that particular location.
Still more leaks will pool around your tired feet and sleepy head as you lay in a coffin-like bed that's sloped, crooked, and hard to get into, and if you're lucky enough to have adequate cushion's below you will smack your head again (when you suddenly wake up from a dream), on a jib-track thru-bolt (the bolt's imprinted scar will be indented on your forehead).
Garbage will pile up, the birds will smell it, and if you leave it in the cockpit they will have their way with it.
Soon after you neatly pack all your belongings aboard you won't be able to locate anything, and you'll end up ripping the entire boat apart trying to find that one camera to laptop cable. Finally you'll just cram everything into compacted wads of disorganization (that will get damp and ruined). The boat will eventually fill up with every useless, non sailing item you bring aboard, rendering your vessel inoperative. You won't know what to do with all the junk that already came with the boat from other's before you, maintenance supplies, boat bits, outdated charts, (warped brushes, rusted primer cans, jelled varnish, mixed stainless fasteners scattered about, fillers, wet sand paper, bits of line, broken blocks, and congealed mystery items that you think are useful but have no idea why. Your limber holes will be plugged, your bilge pump float switch wires will be exposed and shorted, the bilge pump will be upside down and frozen, and cracked, and every hose clamp aboard will be too long and waiting to cut you, rusted and about to break and sink your boat, and half of the cheap plastic thru hull handles will break off when you try and close them anyway (You've already tossed those tapered wooden plugs because you didn't know what they were for). Only one running light will work, no steaming light, your friend will kick off the stern light when he's taking a leak, and maybe you'll have two cabin lights functional, one of them will be half full of water. Your house battery will be mostly dry and frothing at the terminals, and it will be mostly dead anyway once you cast off, failing completely at dusk just when a towing tug is crawling up your arse because you've sailed in its lane. The outboard motor will never keep running long because you've mixed it's fuel with 10w40, the fuel vent on the gas tank is closed, and your friend frantically removed the red kill switch tab before jerking the chord out of the flywheel grove as you yelled at him to get the bleeping motor going, while you were scrambling for the outdated flare kit to ward off the approaching tug in tow.
After Boat US has towed you home (avoid the Coast Guard), and you've passed out in your dank hole you will wake up at 3 AM and lie there wishing you had a refrigerator, shower, and a toilet to snuggle as the dampness from your beer breath condenses and drips on your dehydrated lips.
When a dry spell arrives you have recovered enough to try and re-bed your leaking stanchion bases, but soon give up for lack of access and blob the caulk of the day over their bent bolt heads and cracked deck base. You will eventually spend too much money and time 'fixing it up', doing it wrong, and putting up with local dock ridicule. Within six months you will move off your cradle of love which you paid too much for (even if it was free) and will still be stuck with the slip fees. Your parents will send you early birthday money, you will sleep in your old room, and mom will buy you some new clothes.
After spring break you will return to your still-floating mistress, bail out the bilge, clean everything up, and try and pass her burden's way to another swamp rat.
Having only motor-sailed her once or twice and still not knowing how trim the sails or set the hook, you will soon yearn for a larger boat, more money, then finally come to your senses and move in with your new girlfriend.