You might find the Rainforest Mind blog of interest. Perhaps there is a post in here that speaks to you, that you could share with your father as something *you* could relate too? Talking about your own experiences might be an easier starting place than directly asking about his.

https://rainforestmind.wordpress.com/202...e-gifted-adult/

https://rainforestmind.wordpress.com/2017/07/24/if-im-so-smart-why-cant-i-make-a-decision/