Recently I went to the grocery store and as I entered the alcohol section, I saw a guy stacking the shelves. His hand slipped and the beer can jumped out but he showed impressive reflexes and caught it after couple of fumbles. There was no one else but him and me in the aisle.

I enthusiastically pointed out, "I saw that! That was amazing, great reflexes!" and added that sometimes no one sees these but I will definitely remember it. He was beaming and while I was checking out my stuff, I saw him excitedly pointing towards the aisle and me while chatting with a cashier. Where I am at, it is not the usual to throw loud and vocal compliments at strangers - so I guess he wasn't used to it.

I usually don't compliment people this enthusiastically but I guess the mood and time was right and I felt as good giving the compliment as he must have felt receiving it.

I think a big part of this is that men don't typically receive genuine compliments that often, especially from strangers or acquaintances. When it (rarely) does happen I feel like it can have a significant impact on their mood.