Should i worry about this??

i went to put air in my tires and i noticed that the valve caps were missing and the little threaded washer thingy that screws down the stem to the rim is missing too!! Both tires no less?? i have never had these disappear before. I got valve caps at the auto parts store. The only way to get the threaded washer things is to buy some new tubes. This isn't a big deal because i've only been out a couple of times and i'm still putting things together for the season!! Are those threaded washers really that important. It would seem that not having them would be a good way to stress things around the stem and cause a flat. Just curious what your opinion is.

Forgetaboutit and go ride

or

Tighten those babies down, unless your looking for tube changin practice!

I went to the hardware store but couldn't find any nuts that would match the thread!! :(