Aging sucks! I haven't lost any height but I have lost flexibility. So while I can still ride all my old bicycles without any change in saddle position, the favourite riders have trended towards slightly shorter stems with higher positions. Brifters are also a lot more comfortable than down tube shifters and dual pivot brakes give good braking, despite diminishing grip strength. Indexing solves the worries about being accused of "grinding coffee" when the hearing has deteriorated from decades of wind noise. I won't even get into the gearing changes. However, the biggest inconvenience is the deterioration in eyesight. I can't read my bicycle computer without reading glasses, which means I can't wear sunglasses unless they're those ugly grandpa style or I pony up the big bucks for prescription. Ugh, I may have to buy a helmet visor! Or maybe I could develop a magnifying lens to fit over bicycle computers. Hmmm.