What does my proverb mean?

The closest thing I could find to my proverb, which I assume means the same thing; is you can't have your cake and eat it it too. This means that you can either do one of two things , but its impossible to do both. If you eat the cake you won't have it anymore. Or if you have it, you can't eat it because you won't have it. (1) Or it could mean that something is bittersweet. you may have wished it to happen, but with unexpected and unpleasant circumstances or ways.

(2)"I want to lose weight but I don't want to change my eating habits" says Fred - 
"you can't have your cake and eat it" replies Maggy 

That was all the research I could find on that particular proverb.  Human being's are simply not able to breathe and eat or drink at the same time; else the water would go into our lungs and we would drown ( could draw someone drowned underwater?) Perhaps I could draw mermaids! They can breathe undwerwater hypothetically they should be able to whistle too! I could draw a bar scene but have them all as mermaids.

References

(1)http://www.urbandictionary.com/define.php?term=you%20can%27t%20have%20your%20cake%20and%20eat%20it%20too

(2)http://idioms.thefreedictionary.com/You+cannot+have+your+cake+and+eat+it