I was reminded of this by lisze's comment on 大同小異, where the all too common practice of treating Coke and Pepsi like equals came up. I've never posted it before because I assumed most people have heard this already, but then, I remembered something else: people pick up vocab that is specific to who they are as individuals. You learn words that apply to you, and therefore, the words that I hear all the time (怠け者、食いしん坊、弱虫 etc*) might not necessarily be familiar to everyone else.
舌はバカになっている。
した は バカ に なっている。
shita wa baka ni natteiru.
した は バカ に なっている。
shita wa baka ni natteiru.
The literal translation is at the top of the post: Your tongue is (becoming) an idiot, and while it makes me think of people whose tastebuds are poor in general, it actually is applied to people who enjoy/aren't adversely affected by SPICY FOOD. I love spicy food, so I've heard it a lot,
although I suspect that the average non-Japanese person might also hear it frequently; 
Japanese cuisine tends to be pretty tame in the spicy department, with the notable exceptions of yuzukoshou, wasabi, and MAYBE that karashi that they use to top buta kakuni, but I think they get that from China. Am I missing anything?It's also important for me to remember that the Japanese concept of 'spicy' works a little bit differently than my own. When I think of the word 辛い, and the idea of spicy, I think of heat, the kind of spicy you get from chili or horseradish, etc. Japanese people tend to apply 辛い to anything that is heavily seasoned or particularly strong in flavor. While you can specify that something is 塩辛い (salty) or にんにく辛い (garlicky), it's also acceptable to just call those things spicy. The same goes for things that are COATED in basil. So somebody who excessively seasons their food could also be described as idiot-tongued.
Keep this one ready for your next Korean food outing or your next round of Tako-yaki Wasabi Russian Roulette, and yes, you can use it to describe yourself.
Notes:
- You can use either word for tongue with this expression: した or ベロ.
- One of the reasons that your tongue is described as an idiot for enjoying heavily spiced food is because of the importance of the word 繊細 (せんさい; sensai) to Japanese cuisine. 繊細 is delicacy or subtlety in flavor, and it's the essence of what makes traditional Japanese food Japanese.
- Japanese words for the strength of tastes, from strong to weak: 濃い（koi; strong) ; 繊細(sensai; subtle and therefore awesome)； 薄い (usui; weak)
- If you happen to be in Saga-ken, 濃い is dialecticalized as コユイ.
