"Worthless" - not quite. No percentage-based reduction in value can make something worth 0, but there are extreme examples from history of times inflation has spiralled so far out of control ("hyperinflation"), money became worth less than the paper it was printed on, and life savings became almost worthless.

Can my money become worthless?

Currency is only worthless when people won't take it anymore. ... When hyperinflation hits, that is to say the price of goods goes through the roof, that's another way of saying that people don't value this paper currency anymore.

Is money going to be worthless in the future?

Although paper-based currencies are becoming less popular, they will likely stick around for the foreseeable future. Dollars and cents may become harder to use, but as with many obsolete technologies, there are enough users to ensure demand doesn't disappear completely.