ive travelled alone since i was 11 (im 23) so quite a few times as a kid ive gotten upgraded to first class.
first time it was magical, it was a HORRENDOUS year, my dad past away in a car accident my brother and sister left to the us in search of a better future. and i was alone the whole yeah since mom had to work long hours.
so well she told go visit your aunt in jersey, i flew in continental airlines since my dad has some miles in his account so i used them. when you are a kid you are well you go through everything first since you are accompanied by a airline staff i think the name for kids is UM or something like that.
so you get through customs migration and everything first, boarded the plane (you board after first and business class) after that well the plane took off.
this was after xmas but before new years, i think it was december 27th of 02. 30 minutes or something into the flight they told that for a latte xmas present they had an extra first class seat. boy i was excited, i got food, unlimited sodas i nice turkey meal. wonderfull stuff directly to the newark airport. that was my best memory of first class tho.
last time i did was in 2012 boy was i happy to have miles for a first class ticket i did Orly-Barajas-Lima my connection from barajas to lima was a whooping 14 hours. thankfully if you have a first class ticket you are allowed on the vip lounges and shit. meaning free internet, haagen dasz ice cream(i dont get them here in peru), beds, snacks, jamon iberico (or serrano i dont recall) and of course showers. funny thing was that when i went in to take one hot water like ran out or something

had my head covered in shampoo and had to take freezing water (it was winter).
the flight well everything nice but upon landing i saw the faces of the regular folks, it was like they wanted to kill someone 14 hour flight with little to no legroom

that mustve sucked)