Am I losing my mind?

I was chatting to my friend the other day and we were discussing the merits of those small, balance bikes for kids.  Obviously, we mums,  are all in favour of our kiddie winks being given the opportunity to learn to ride bikes at an early age. You know how playground chat goes, 'My child could ride a bike at 4 years of age.' Another pipes up, 'My child mastered a two-wheeler by 28 months!' (At what point should we stop referring to our child's age in months?! Never quite sure.)

Meanwhile, I recall that  my third child had approached school age and we had forgotten to remove the stabilizers from his bike!  In determination not to make the same mistake with child number 4, I remarked that I would buy her a balance bike for her 3rd birthday which was coming up in November.   To which my friend queried, isn't her birthday in March?! Horror of horrors, I had forgotten when my child's birthday was and I was out by a good 4 months! Was I losing my mind?  Made a quick note to self, go home and Google, 'early onset of dementia!'