Show and Don't Tell

Show, don't tell.  

True love is the greatest thing in the world...Except for a nice MLT. A mutton, lettuce and tomato sandwich, where the mutton is nice and lean and the tomato is ripe. 

It's a beginning writer's mantra.  Perhaps, it is even an apt collection of words to tattoo across the top of a novice scribbler's hand.  Do not tell the reader that your character started to feel old, instead show them.  

Let's draw on personal experience, shall we?

Today I strained a muscle in my hand using a three-hole-punch.  I was all alone in my office, yet I still pretended it didn't hurt.  It hurt like hell, and while I struggled to remove the paper that was stuck in the middle punch, I blushed in my own humility.  Then I ripped the stack of sheets in half trying to free them from the middle-punch choke-hold.  Yes, it was barely audible, but I still said it:  bloody hell, I'm getting old.  

How else could you show your readers that a thirty something is starting to feel the other side of the bell curve?  True, I now choose VHI over MTV, and sometimes diss food by saying it "doesn't agree with me."  But after today, I have to say the best "show" is to describe  a wimpy injury sustained while doing a simple task.  As an other example (identity redacted for protection of masculinity purposes), a close relative of mine, who shares the same birth date and year, blew out his back making tea.