I have >20x my student loans in cash / liquid investments, but can't bring myself to pay them off

I yearn for the day that I can post here celebrating my student loans off, but I only get charged 1.9% interest on them and my investment returns obviously far exceed that.

Anyone feel this (incredibly first world problem) pain? And if so, did you just pay them off? Do you regret it or has it changed anything for you?