The World Cup Wallchart

At what age does it become unacceptable to pin up one of these? I think the serious collecting of Panini stickers has to end before you reach double figures, though I am collecting this year, so there. The World Cup wallchart is a different matter. I seldom remember filling one in right to the end. They usually get ripped off the wall once England has been eliminated. Plus it's tricky finding a pen that'll let you write at such an angle without the ink running to the wrong end of the pen, which soon becomes annoying.