No good at saying no

y resolve about not taking on new things is weakening.  I was asked last night to step in as treasurer for my Toastmasters club, because our current treasurer has just resigned from the club.  My immediate response was that I definitely couldn’t do it after the start of July, because I’ll be studying, but the President assured me that was all they’d need – club elections are in June, so I could step down then.  So I’m starting to think maybe I’ll say ok (but with the strict understanding that it’s only until mid-year) – I’ve been in the club long enough and I’m getting enough out of it that I’m feeling like I should give something back.  And being treasurer is a job I could do with my eyes closed, so I can’t imagine it being all that onerous.
The only danger is that if I say yes, I then go on everyone’s mental radar as “person who will volunteer for stuff”, so I’ll keep being asked to do more.  But having those 5-month blocks of total unavailability when I’m studying will help with that, because I do stand very firm when it comes to not interrupting my study time.
So… maybe….?