What age is safe for bubbles?

Could you elaborate on the concept of "safe age for bubbles," please? I'm somewhat puzzled by the phrase, as it seems to combine two unrelated ideas: age and bubbles. Are you referring to the age appropriateness of children playing with soap bubbles? Or perhaps you're inquiring about the safety of investing in bubble-like financial assets, such as cryptocurrencies or overvalued stocks, at a certain age? Could you clarify your question, so I can provide a more accurate and informed response?