Might get flamed for this, but I'm now 9 weeks into BFing my 2nd baby and remembering that I feel like a different person while BFing.
I feel a mixture of good & bad changes: on the minus side, I'm more emotional & worrisome, less efficient, more forgetful, and feel I'm on slo-mo all the time.
On the plus side, I am less likely to sweat the small stuff, less concerned with the views of people who don't matter to me, more likely to say "WTF" and put my feet up, much more loving, and more deeply appreciative of art & music.
I try to take into account sleep deprivation and general life adjustment, however I remember that when I stopped bfing DD at 9 months, I had a strong sense of my lights being turned back on about 2 days later.
It's not a bad thing really, but I am so grateful for decent maternity leave!