My mum is 89.  I knew this but hadn't followed the knowledge through to the obvious conclusion that this means next April she is 90.  Only a chance remark by a friend on the planning going in to his mum's 90th birthday celebrations made me realise that maybe I wasn't totally focused on this momentous event.  Anyway my mum may have memory problems but, contrary to what Ash has always thought, she's switched on in every other way so I thought I'd better find out what she wanted to do.  The conversation went like this:

Me: what would you like to do for your birthday next year?
Mum: Oh that's ages away we don't have to think about it yet.
Me:  But you're 90 which is special so maybe we should start planning.
Mum:  Well I don't want everyone to know I'm 90.
Me: So you don't want a big party then?

At least that's one less thing for me to think about although it won't go totally unmarked regardless of what she thinks.