It is better to take precaution and avoid things caused illness than to fall ill, then try to get cured
And it is better to prevent accidents of all kinds by being carefull than to let them happen through carelessness
and then try to repair damages
It's both Thai and english proverb
It means that is valuable
it can be used to mark a lot of money in your work and business
so wasting time is like wasting money
Don't waste your time!