Taking things for granted - Mr T

Good morning boys.  Have you ever taken anything for granted and then been 'brought back to earth' with a jolt?  What does 'taking things for granted' actually mean?  How can we possibly, consciously, think through and appreciate everything that happens to us?  How often do you appreciate that you can hear?  Can see?  Can walk?  Two weeks ago I picked up a running injury after completely missing a kerb about 8cm high.  I cannot run at the moment and it has got me thinking about taking things for granted.  I now really miss something which was so ingrained in my life that I probably did 'take it for granted'.  I am annoyed, frustrated, grumpy and now, possibly because of my body 'letting its guard down, crook because of it.  I think there is a link between mental health and physical health.  What do you think you take for granted the most?  Is it OK to do this?  How can you fix it?  Do you know a good story where someone has taken something for granted so badly that they have come 'unstuck'?