I think there's a difference between being prepared and setting yourself up for a fall
Yes, be aware that there are risks, as there are with any labour, regardless of it being a VBAC, and be prepared to have your plans changed if the need arises, but please try to think positively and believe in yourself. VBAC is the safest option for both you and the baby at the end of the day which is why most units encourage a trial of labour these days rather than going straight for a second section. Yes, there are always sad stories and bad outcomes, but this is the same for any labour.
I had a VBA2C, only 17 months after my second section and although I ended up with an assisted delivery, I would go for a natural delivery every time given my recovery, both mentally and physically after the VBAC. And things going wrong, like scar rupture, are less likely than a cord prolapse in any given pregnancy, but no-one scares us sensless about that do they?