The best motivation is to prove someone wrong.  It’s not “Goody two shoes” motivation but it’s very effective. Usually one might be lazy to dive into some off bit topic that are otherwise might seem boring.  However, if someone calls you on the dissemination of erroneous information or ignorance that would motivate you to dig deep until you prove your point and overthrow your opponent in the abyss of public shame.

Interestingly, while doing it, your original opinion might undergo significant changes or sometimes, change completely.  More so, sometimes, you might find out after significant research, that your opponent was right. (trust me that also might happen)

However, in the smoke of a battle, the original point would drift to such oblivion that you might hide your “defeat” from your interlocutor and most importantly, from those following your discussion. 

Still, in the end, you will win as you now will know something that you otherwise would be hardly motivated to learn. )))