Most of today's finds, at face, will not come around again. If you can, keep it. I kept many as such in the past and still have them. remember you can still spend them, or you may find out later that they do go up in value. So, flip a coin, and see if you keep it or spend it.
Spend it. It has lost at least 5x it's purchasing power since it was issued, and will continue to lose more. $20 today is what a $5 bill then (1950-1963) would buy.
As long as you know it is incredibly unlikely to significantly go up in value and don't mind tying up $5 (that could be spent on another coin or note, perhaps? ), then keep if it you like it. If you're collecting older bank notes, then the advice that @NOS and @SteveInTampa gave is excellent
I have a series 1950 5$ that I found a long time ago. I kept it just because I like the light green color of the seal and serials.
Kindly note that your use of "it's" should be "its" as writing "its" in the possessive context is the same as writing "his", "hers", "yours" or "theirs". Anyway, this is not a $50 bill or even a $500 bill that is being discussed but a $5 bill so loss of value due to inflationary pressures will be negligible. Like has been previously mentioned, $5 won't break the bank (except perhaps to you?).
I have the 5 displayed along the edge of a clear round container along with a few nice clad Eisenhower dollars (also from tellers). I will name the container "Hopeless Investments". All joking aside, I completely understand the investment point of view. Most of the time, I try to do a fire drill with coins or paper that seem like a good deal. Instead of buying them, I add the same amount to my index mutual funds and watch the numbers grow. For me, the numbers on the computer screen lose their charm quickly. There is never enough! Perhaps the same is true for collecting silver, gold, paper, coins...