I didn't shake at all when I took the high-speed rail two years ago, but now I feel very shaken when I take the high-speed rail. What happened? Is it an illusion?

Because of business trip, I often set out from Xi 'an to the north and south. 13 years, Xi' an and Beijing often run, feeling that the high-speed rail is very stable. These two years feel like the Spring Festival in Wang Xiaoer, getting worse every year. Hengyang and Xi 'an also often run, feeling very shaken, which is nothing compared with previous years. Why can't coins stand, and a full glass of water won't spill? This is even more nonsense. I haven't met it anyway. Am I on a fake high-speed rail? Now I'm on G832, which makes me dizzy.