In case it wasn’t a typo, and just to help OP for the future…

It’s “this day and age,” not “this day in age.”

I know I’ll probably get downvoted for the pedantry here especially since everyone understands what was meant, but hopefully OP will appreciate the information about the common phrase.

Also to answer the OP’s question: inferiority complex. It runs rampant in society, especially among men.