From 16-20, I worked in a foundry, behind the bar at my local and on Saturdays in shooting season, I was a beater, went into furniture making while still doing bar work. Got laid off from the furniture place, so went into full time bar work. Had a big motorbike accident, so no work for two years and was limited to what I could do. Got into computing and did several courses, which led to me working in road haulage, becoming the transport manager from 1990 to mid 2010. Had another life changing accident on February 29th 2008 (yes, Leap Year Day), the day my working world ended forever. I got back to work for a little while, then my employer went bust, leaving me with very little in the way of options, the injuries I suffered took their toll and I was no longer able to work, now, I'm medically not allowed to work, I'm in the support group within the DWP and it cheeses me off that I cannot work, both mentally and physically. For a guy who was working full time and more, to a full stop was a huge loss in my life, I loved working and being busy all the time. Now, the pains, stiffness and recently diagnosed Fibromyalgia, control every aspect of my life and I can tell you, it's not pleasant.
Enjoy what you have, while you can, one day, it could change in an instant, then the regrets can bear down on you, heavier than you could ever believe.
Live for today.