Enter the main post office building through the main doors. You'll know you're there by the giant tiled mosaic of ancient Rome. It's impressive but don't let it distract you. Don't dwell. Don't gawk. Turn left immediately and a few steps further on you'll see the door marked telegrams. The forms are in small containers atop the wooden countertops that frame the dilapidated oblong room.
The forms are greenish, with the words Telegramma dello Stato printed at the top. Don't be alarmed. The state doesn't own your telegram. It does own the postal service that will read your dispatch and send it via sub-oceanic cable.
Always bring a pen. There are none on the countertops and the clerks are stingy. The night shift clerks are determined skeptics. They won't give an inch. They'll tell you they don't have a pen. Buy one, they'll say. You can't of course; it's too late. All the pen-stocked tobacco stores nearby are closed. So bring a pen or a blunt pencil. Be sure to press hard.
Unless you make a million lire a month (money to burn), begin the text with the letters LT, or Letter Telegram. That'll buy you 21 words on the cheap. Exceed that with a single character and they'll sock you for a full-charge cable.
Don't let them. Weigh each word. Curb your passion. If you want to write, "I love you madly," write "Ever" instead. Allow for inference, but not too much. If you're applying for a job, do not write, "I want the job" but "hire me," which in all-capitals tickertape will emerge as HIRE ME. That's clear enough.
Don't bother the clerks while composing your text. They're smoking, at least after midnight. It's an arduous act of repetition.
Do not sob if you grow emotional. It won't sway the clerks. They won't sympathize or speed up. They've seen it all. Stay cool.
When you're done, make sure all your letters are clear. Though the clerks know English phrasing well (experience counts), don't assume they'll repair your errors. They might say, "What is this? I cannot read it," and send you back to recompose the whole. If this happens, show no bother. If necessary, do it again. This might also give you a chance to reconsider, to defer rage or bias, perhaps even to put aside the cable until you've thought things through more clearly.
Always pay professionally. Do not extract crushed bills from a dreary damp pocket. This will speak poorly of your status as an adult, at least in Rome. The scoffing clerks may act less swiftly. They may place your cable under a mineral water bottle and send them only at the end of their shift.
So, use only flat, clean bills. Bring change, since they rarely have any. Thank them afterward for their attention. Be polite. Never raise your voice. And remember credit cards are meaningless.
If you must ask when the telegram will be delivered, know they'll always say the next day. Do not debate delivery times. Every minute counts toward the expedient sending of a message. Talk too much and you're working against yourself. The clerks must type your message on a double-decker Teletype machine; so let them get to it on the sooner side.
On your way out, nod and say buona note. You might be seeing them again. They're fixtures. They remember faces. Leave the same way you came, out the door, this time to the right, your back to the grand mosaic.
If you need a cab, remember there's a night charge. As for buses, you'll find them in clusters at the Piazza San Silvestro terminus just outside the post office. Some buses run after midnight but don't expect timetable precision. Remember a city exists in part to frustrate you. There's no smartphone to save you. Be resourceful. Take in the ancient. And be prepared to wait.