over your head

از سرت هم زیاده

مثل خر در گل گیر کردن be in over my head

لقمه گنده تر از دهن برداشتن.

فراتر از فهم و توان کسی

to be involved in a difficult situation that you cannot get out of

over your head = beyond your understanding
فراتر از فهم کسی
ex: The professor was speaking over our heads, None of us could understand him