Are you sure?
```ruby
irb(main):001:0> "asdf".start_with? "a"
=> true
irb(main):002:0> RUBY_VERSION
=> "1.8.7"
irb(main):003:0>
```
```ruby
[1] pry(main)> "asdf".start_with? "a"
=> true
[2] pry(main)> RUBY_VERSION
=> "1.9.3"
[3] pry(main)>
```

Unless I'm an idiot and managed to monkeypatch String in an init file somewhere.