...couldn't stop wondering how ubercool the city has become since I last visited in 2001; granted I was a poor student then and a street stand hotdog seemed like a fortune; Manhattan is still freaking expensive though :)
...wondered how in all stores they seemed to have double, swinging doors without any PUSH/PULL sign on them; basically this gives you four separate ways to approach the problem; I usually succeeded on the third attempt;
...was appalled at no cell reception on the subway before I understood my commute from Brooklyn involved passing 20 m under the bottom of the Hudson river, as my eardrums faithfully attested at each go;
...I found a credit card compatible soda vending machine;
...I found my VISA card to be refused everywhere in stores but not online; so I called the Belgian bank and aparently the US is considered a particularly dangerous destination for Belgians, you need to have your card specifically unlocked for US usage before the trip; luckily you can do that over the phone!
...found street names to be very straightforward but the subway naming system extremely confusing (is the station on the corner of 46th street and 5th avenue gonna be named 5th avenue or 56th street? that was always the question!) 
...went to the Top of the Rock and skated at Rockefeller Plaza ice rink, where I was the most skilled skater among the crowd of stumbling Brazilian tourists;
...noticed how the city was in a humongous hurry all the time and even I, a lover of big towns, was sometimes baffled and overwhelemed, especially at busier subway stations; the crowds, the noise, the impatience - all world class!
...marveled at the skill of street musicians at subway stations - the range-> anything from Chinese folk to reggae to BritPop to opera; the talent level-> usually nothing short of recording artistes IMHO...
...was pissed off at how my GPS was constantly thrown off in the shadow of gigantic skyscrapers in Manhattan, it was a bit like walking blind most of the time; or asking people; which amounted to the same thing;
...saw the funniest beggar notice where a guy had a sign over his hat on the ground saying: "I bet you a quarter that you read this!"; I lost of course :)
...was overjoyed to find large stores in Manhattan all offer toilets to their customers on the premises; that plus the sales clerk commitment and helpfulness really made me not miss Belgium; not at all;
...tried 10th and 9th best pizza in NYC according to Village Voice; they were both outstanding; all the remaining 8 were in Brooklyn (one in Staten Island), I'll get to them later :)
...had as much Mexican food as I could and though of varying quality at street stands, sometimes it was pure bliss;
...ate myself the legendary cronut; the line wasn't even that long; good, I preferred the Gingerbread croissant from the same bakery though; 
...visited the famed 5th Avenue Apple Store; it's 24/7; at 2am on a Thursday night it was bustling and hustling like a Belgian boutique at sales day; incredible;
...saw the 9/11 memorial where I once went up the lookout on the roof of the WTC, 14 years prior; sad and baffling at the same time;
...took two cruises - one around the Manhattan and one to the Ellis and LIberty Islands and climbed the crown of the Statue of Liberty; she's very tight inside!!! oops, that came out wrong..
...took an aerial tram to Roosevelt Island, ate bacon flavored chocolate, walked around snowy Central Park, went to a not very funny but quite genuine stand up comedy show and generally did a lot but missed on a lot more so I will be coming back very soooooon hopefully!