Can you imagine knowing that when you hit 35 you have a brain injury due to an A.V. malformation, almost die, wake up in hospital, become permanently disabled and have to learn to walk again?

...Yeah...

having all the skills, memory and mind of a fully mature person trapped in the body of a baby

Trapped?

I'd not be able to contain myself, and would speak, and ambulate, immediately... wowing people to such a spectacle... a talking dancing baby, who can espouse advanced philosophical notions, challenge people to reflect on their epistemology, and even warn of crooked ploys put upon the world. ... Oh dear... I did not want to become a religious icon.

I'm presuming the baby continues to grow up normally, and is not an eternal baby-body prison... and that "all the skills" includes psyche-motor skills. ... And best of both worlds, able to learn like a baby too, vividly retaining near everything, contrast to old-man brain (where decades of toxin accumulation and stress have impaired neurogenesis and learning capacity).