What's the most important lesson you have learnt?

That it never stops hurting when you fall off - after 40 years of riding I can confirm this. Although, I think when I was younger I got over the aches and pains a bit quicker. Now I am limping for days :(
 
That when my horses don't 'do' what I want of them, the onus is not on them to change their behaviour and actions but on me to change mine.
 
If there is something that can go wrong with a horse - it probably will go wrong - and it's very expensive.
 
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