We're in violent agreement. (Though you've gone much further with rust more quickly than I - libregex is beautiful.) A couple thousand lines to feel pretty solid with lifetimes sounds about right - I'm getting close to that range and the issues I'm hitting are increasingly of the obscure kind rather than the initial "nothing works, I guess I'll put it all on the heap!" kind.

This is basically why I said if you consider this a downside. I think it's only a "downside" in the same way that purity is a "downside" in Haskell - it isn't accidental complexity, and wrapping your head around it is just a part of really learning the language.