>>>>Never look a gift horse in the mouth.
>>>
>>>Great! I didn't know, what this expression exists in English. In Russian we have the same proverb: "Darennomu konju v zuby ne smotrjat" :)
>>>
>>>Thanks.
>>
>>
>>Now do you understand the basis of the expression? That the age of a horse is best shown by the condition of the teeth...
>>
>>Peter :-)
>
>Yes, I knew that... Thanks for the further explanation...
>It's interesting for me to find out the Russian/English proverbs analogues. Now, the question is: which culture invented this first :) Also I'd like to see some other examples...
>
>Thanks in advance.

How about:

"A stitch in time save nine."
"Never put off what you can do today until tomorrow."
"The early bird gets the worm."
"Alway let sleeping dogs lie."

And my personal favorite...

"Always make a point of going to other people's funerals, otherwise they may not come to yours."