think nothing of it
• do not apologize or feel bound to show gratitude (used as a polite response).
think nothing of
• consider (an activity others regard as unusual, wrong, or difficult) as straightforward or normal.
• "ordinarily, our elected representatives would think nothing of spending another $20 billion"
Similar:
consider normal,
consider usual,
consider routine,
take in one's stride,
not think twice about,
have no problems with,
have no compunction about,
have no hesitation about,