Can you roll your tongue?

I can't roll my tonuge. However my mother and father and siblings all can. Doesn't the dominant allele overrule the recessive allele? So if my mom has the genotype Rr (R= can roll tongue r= can't roll tonuge) and my father's genotype is Rr too. So shouldn't it be guareented that I can roll my tongue. Shouldn't I still be able to roll my tongue?