Beyond somebody’s wildest dreams
Definition 1 of 1
Pro Tip 1/3Extreme Outcome
Use when an outcome is so good, it seems almost impossible or unimaginable. 
She achieved fame beyond her wildest dreams after her performance went viral.
Pro Tip 2/3Positive Surprise
It expresses a level of surprise and delight when something turns out much better than expected. 
The startup's success was beyond the founder's wildest dreams.
Pro Tip 3/3Not Literal
It's a figurative expression, not meant to be taken literally; it's about imagination, not real dreams. 
His art sold for amounts beyond his wildest dreams.