Responsibility is expected even from young children (e.g., 5-6 years old).
The example of a lost tupperware highlights that initial leniency for forgetfulness evolves into a demand for accountability.
This expectation of responsibility applies to all personal belongings, including clothing and school items.
Marking personal items with initials or names is important for identification and demonstrates care.
Lack of personal responsibility can lead to carelessness and indifference towards belongings.
Items can gain significant value, called 'nisbat' (attachment or association), beyond their material worth, especially if given by respected individuals or associated with sacred places.
An example of 'nisbat' is how a former toilet area at the Kaaba became highly valued once it was incorporated into the Masjid al-Haram.
Similarly, ordinary paper becomes valuable when Quranic verses are printed on it, due to its 'nisbat' to the Quran.