22. You'll Think It's Autumnal, They'll Think It's A Heatwave
You're sitting on the tube in a woollen jumper and leather boots and they're putting up signs telling people to carry water with them and not freak out if liquid appears on their skin, it's just sweat, it's totally normal. That's when it dawns on you - this is the warmest it's going to get. All. Year. Don't panic. You'll get through this. Embrace thermal leggings and learn to rock hats and try not to laugh too much when people appear faint on a 22 degree day.