Why does adobe flash player want to download on every website I try to go to?

After signingin to my website, and trying to go to another thru a visual tag, I get a message from adobe to doenload the flash player. Isn't once enough?? Can't the programmers send a tag to see if it has already downloaded the flash player??

I'm just an old fart, but they should get their heads out of the sand and put a tag into the add on tag to see if the flash player has already been downloaded. If so, continue with the site downlosd.

This crap just makes it harder to access websites.