DS 1, 21 years old and at Uni, is an affectionate and generally pretty caring son - though he can (like any of us, I guess) be very thoughtless.
Anyway, AIBU to be a smidgeon sad (actually a bit more than that) that he hasn't phoned me to wish me Happy Birthday (or texted or left behind so much as a card when he was taken back to Uni a few days ago)?