Is it you getting old or your components?
We all know about keeping our drive train clean and that chains, gears and bearings wear out, but what else could be affecting the way you ride?
A big one is pedals. How many of us check our pedals regularly? Probably not many. This GIF is of pedals with new cleats, but about 24,000 Km wear on them. Some people might change the cleats when things are feeling a bit slack. Some may even strip the spindles down and either service or replace bearings in the pedal, but its important to look at the mating faces of the pedal. Pedals can get worn and cause the cleat to move vertically in the pedal resulting in new pains, normally in the knees. Have a check of your pedal float, sideways is normal depending on cleat choice, Vertical movement between your pedal and cleat is a tell tale sign your pedal has maybe seen better days.
The interface with the pedals is very important. All your effort is transferred to the bike through your pedals, so it is a must to keep your cleats and pedals in good condition and ensure the fit is correct.
Other components can fail or wear over time such as saddles, seat posts and even crank arms, but these are much more uncommon and tend to be issues caused by misuse or a crash but not always. We have on occasion seen cranks with cracks that allow the pedal to bend in towards the bike and saddles that have one rail starting to fatigue allowing the surface to tip to one side. If you've dropped or crashed your bike and on first glance not seen any damage but subsequently get discomfort, have a closer look at these areas to ensure nothing is bent or out of alignment. Fitment is often down to mm's so small faults can cause big issues.
Time isn't such a good metric for some people for component replacements, if you're a high mileage user then maybe a check of component wear is better than 'it was new in August!'
So when you get new pain on a bike you are used to, ask yourself are you getting old or are your components.