"I thought the lemon drops and lemonade removed the pain."
Albus smiled. "They help with the next day's pain. You had the glasses last night, so they acted as a buffer. Additionally, I was wrapping you in magic and adjusting my magic, so that also acted as a buffer. Normally, activating one's ability to see magic is accompanied by feeling as if one has white hot knitting needles stabbing one's eyeballs. Adjusting one's magic to match a ward makes one's nerve endings feel like they are being scraped with a cheese grater, where each additional adjustment ramps up the pain. I can get up to around 40 adjustments before passing out from the pain. Anything more than 30 adjustments though is pushing me to the point where I start to become useless in a fight. Of course, adjusting one's magic properly also requires one to already be feeling the searing pain of looking at magic, so you can probably understand why it's rare for anyone to have either ability."
Harry stared at Albus in horror. "But… you didn't act like you were in pain last night."
Albus shrugged. "Oh, it was pure agony Harry. But, decades of practice have allowed me to compartmentalize the pain where I can function as if I am not even remotely uncomfortable. It was a useful skill to have for the one time that Tom tagged me with a Cruciatus torture curse, and I responded as if it had no effect. He was so unnerved that he fled the battle and that is when I got the reputation as the only person he ever feared."
Harry wasn't sure if he should be impressed or scared for Albus's sanity. "Could you have broken Malfoy's wards, instead of putting yourself through so much pain?"
"Easily, yes. Not quietly, of course. But I could have done that."
"Then, why did you do the more painful option?"
Albus smiled. "That is an excellent question, Harry!