When you run into someone who is disagreeable to others, you may be sure he is uncomfortable with himself; the amount of pain we inflict upon others is directly proportional to the amount we feel within us.
If you're trying to achieve, there will be roadblocks. I've had them; everybody has had them. But obstacles don't have to stop you. If you run into a wall, don't turn around and give up. Figure out how to climb it, go through it, or work around it.