Aiyah, if you full time student they won't bother you till you
graduate lah.
I was away for 4 and a half years, didn't hear from them once. 8
months after I grad, ICT letter came. Kena sent back to old unit.
After old unit ROD, kena post to new unit, so don't worry your turn
will come. 
As for not being called up even though not student. Met this fellow
who didn't get his call up even though he called a few times to
check. Eventually got his call up for ICT...
....7 years later! Darn sway. Almost everyone in reservist unit
younger than him.
Oh, and as for the guy that said you don't need to carry anything
with you to your reservist training on the first day... Follow his
advice at your own risk.
If you go combat unit, no such thing as book out 1st night. Well,
at least not before being tekan and most likely charged by
RSM.
Try to find out from your unit lah. Besides your online SAF100, if
your unit on the ball, they should probably send you reminder
letter along with what to bring and at least one contact number to
call. Check there.
However if you combat unit going for high key ICT, my advice is,
just bring your FBO. Odds are you're gonna need it. Good luck!