We’ve all been there: we’ve all risked it in rush hour, gone up to the top deck knowing the odds but giving it a go anyway, tilting our chin up, peering expectantly looking for a spare seat while also trying to discreetly check why it might be free. And there you are in front of everyone, head bobbing side to side, squinting down the bus. A pointless move at this time of day and everyone knows it, so you have to retreat quietly back down the stairs while, you imagine, the seated roll their eyes at the back of your head.