Go on stage because you have a sudden desire to? (3,2,7)

'go on stage because you' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'a sudden desire to?' is the wordplay.
I cannot really see how this works, but
'a' is present in the answer.
'desire' could be 'impulse' (impulse is a kind of desire) and 'impulse' is found within the answer.
'to?' could be 'to' and 'to' is found within the answer.
This explanation may well be incorrect...

'have' acts as a link.

Can you help me to learn more?