"I used to have a bike..."

[wiltshire builders]

My pet peeve is "I couldn't have a bike, I'd kill myself"

You wouldn't say "I don't go swimming because I'd drown myself" or "I don't do any cooking because I'd accidentally knife myself to death" but somehow it's not moronic to say that riding a bike would result in instant death

That really made me laugh!
You're quite right.
"I'd kill myself " sounds a lot more macho than "I'm scared that I might get knocked off and hurt myself "
I might use the cooking excuse thought...