Does anyone else like attempting to spend obsolete currency?

I'm in New Zealand and every now and then I will bring a $2 note or some old large 50/20/10 cent pieces to a store just to see if they take them.

I only do this with common items without much numismatic value of course, awhile ago I tried to buy chicken and chips with a modern $10 note and 70 cents of obsolete coins and the cashier just let me have it for $10 and told me to keep them

Might be fun to try this in England or any other country with lots of near worthless out of use coins 

They aren't obsolete but most of my cash purchases in the US are made with half dollars, dollar coins, and two dollar bills. I also usually leave one of each of them as part of my tip at restaurants. (That's all I carry except for some $20 for large cash purchases and – of course – various non-US coins and bills.)

Some people have never seen the half dollar coins. That's not surprising as they weren't produced for circulation for most of the lifetime of most cashiers. Some think they are valuable (especially the $2). And they often have trouble making change.

My local bank will order in bulk. I'm not sure why it benefits them to order $2 bills or half  dollar coins for customers but they do it.

Last time I used a $2 bill at a quiktrip, the woman at the register gave me a very sarcastic “coooooool" and then looked annoyed that she had no slot for it and picked up the whole drawer and stuck it underneath. 
 

The last time with a half dollar, the young girl flipped it over back and forth a half dozen times. I'm not sure she'd ever seen one before. I haven't spent a brass dollar in many years but usually everyone looked at it like it alien money.