Being a grump really doesn't feel very good, nor does it serve us very well. There is a reason for that age old saying, "you catch more flies with honey than vinegar."
Setting aside, for the moment, the question of why one would want to catch flies anyway, let's examine this concept a bit.
First of all, we all know that what we embody, what we be, what we do, what we put out there.....is what we attract. Right? If you don't know this, or don't believe it, try an experiment. Go to the grocery store and be rude. Steal a parking place, don't make way in the aisles, take cuts at the check out line, and whatever you do.....don't smile at anyone. Check out how that feels, and check out how people reacted to you.
Now go back in the store. Smile and make eye contact at everyone you encounter. Help a short person reach the item on the top shelf. Let the person behind you in the check out line with just a couple of items go in front of you. Check out how that feels, and check out how people reacted to you.
If that isn't enough to prove the concept, do your research. Don't just check out Law of Attraction sites, which can admittedly be biased. Check out some quantum physics. Check out the "observer effect."
It really is true, we attract what we put out there. In terms of feeling grumpy, simply smiling could change all that.
If you did the experiment above, you've already seen that smiling will completely change the way people act towards you.
Now try this:
Smile. All the time. Even if you don't feel like it. People will wonder what you are up to. And I guarantee it will make you feel better.
And try counting how many smiles you see in a set period of time. Go ahead, count those smiles! For an hour a day. Write down how many you get. Do this every day for a week.
Then see how you feel.
It's true: we can change our feelings by smiling. It's a behavior modification technique that is simple, easy to do, and very effective.