Are you a host to parasites? Even to strange parasites?
You do all the paying for your friends all the time. Even if you come last to the table and eat just a snack as they gulp down all varieties available, so long as you're there, they never use a coin to pay for a thing.
When there's a timeline to get something done at work over the night, they look at you. They know you will be ready to give up your plans to come to their rescue.
You lend your stuff even when you need it. Like that time you gave your laptop because that other person's had crashed, despite having an assignment to finish.
When it's lunch hour, everyone starts asking where you are; they need their lunches and you are their ever ready 'errand boy/girl'.
Your housemates leave a bunch load of dishes in the sink and you wash them despite having been away for a week. Matter of fact, as you do your laundry, one comes with their week-long dirty laundry and offer to do it (as you always do).
People pass you by at the queue and you silently stand there like a dummy even when they're not kind enough to ask.
Your lecturer splits the class to groups to give an assignment. Your group mates leave you to do all the research, compiling and presenting.
Sure enough, it is an honourable thing to help. But it shouldn't be in a way that you let others use you, taking advantage of your good nature.