I didnโt, i was about 5 at the time, but still remember that experience 
Normally back then you would take condensed milk (i prefer unsweetened) can and boil it for about 3 hours to make the filling. Its very close to Dulce de Leche. Back then we didnโt have premade stuff being sold. Be careful though i only done it a handful of times (boiling it) so make sure no part of the can is ever exposed to the air and always have water covering it.

