Is it normal that i sometimes feel like beating people up?

Sometimes students at my college have no problem just throwing away their trash into the back of my pickup truck as if it was a trash can. Last semester I found 2 pizza boxes, without pizza mind you, in the back of my truck and it totally pissed me off. Yesterday, I found several candy wrappers in my truck. I always have the feeling that if I knew who these people were, I'd love to flip out on them or beat 'em up, but then I probably couldn't because I'm just a short and thin 5'8" 20-year-old virgin with barely any fighting ability. And today, as I was counting some change in my truck, a group of college guys walked passed me and into their car and one of them held up and placed a stupid clown mask from McDonald's over his face and looked at me for a few seconds as if he wanted to get my attention. Things like this have happened to me once in awhile throughout my life and I've just had it! It's not like I'm a hermit who hates people. I have a few friends and I told one of them that I sometimes feel like beating boys/guys up who look like jerks and he laughed. I could be overreacting here but I would just love to kick that kid I saw today with the clown mask in the nuts or punch him in the nose if I wouldn't get beaten up by his friends for it. What do you think?