Hard to get past

[Xinfu]

-'I suppose you think you're harder to get past than a pack of enchantments!' she stormed. 'Enough of this nonsense! [...]

What does 'hard to get past' mean here? If you say someone is hard to deal with, then it's understandable, but Potter and company would not think they themselves are hard to deal with.

[Rusty]

... harder to defeat/overthrow
... harder to avoid/get around

[Xinfu]

Thank you. But why would Professor Mcgonall think that Potter and company think themselves harder to defeat than spells, etc?