Accept the past. Live for the present. Look forward to the future. Robot Fusion
"As our island of knowledge grows, so does the shore of our ignorance." John Wheeler
"[A] scientist looking at nonscientific problems is just as dumb as the next guy." Richard Feynman
"[P]etabytes of  data is not the same thing as understanding emergent mechanisms and structures." Jim Crutchfield
I havn't read the rest of this thread so I'm sorry if I'm repeating advise stated prior.
What I've found significantly helps:
1. Find sympathy for others in yourself
Once you find sympathy for others (or rather once you become the sort who doesn't judge, belittle or become angry at others) you'll find it much easier to do so with yourself. You don't have to delude yourself in order to interpret others and yourself in this way. Once you are willing to understand why people are the way they are its easy to find a real excuse for their limitations/actions. It must be emphasized you aren't turning negatives into positives. The goal is merely to understand fully each occurrence at hand with a good will. Sympathy should follow.
2. Be humble, or rather, be realistic
It is very easy for an intelligent mind to perceive their lack and thrash against it, causing self-dislike. If someone has a clear and extensive list of their own limitation, and a tendency to remind themselves of said limitations often, of course they won't like themselves. The key is to be realistic; though many people would call this being humble. We lie to ourselves all the time, and are encouraged to do so. Remind yourself of the humble truths; you are only human and as such are exceptionally limited in compassion, intellect, memory, foresight, wisdom, lack of body odour, confidence and impartiality compared to the actual total possession of these traits (as held by a God, though I do not believe in one). Note Einstein:
"Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."
I'm sure he included himself in said stupidity.
3. Never determine your value by comparing yourself to others
If you compare yourself to another and find yourself superior, you might well oscillate between arrogance and guilt over feeling superior. Also, you may limit your own growth by setting the bar too low. "I am already the best."
If you compare yourself to another and find yourself inferior, you bring unhelpful motivations into your actions. One is at risk of losing track of more personal goals in the general pursuit of status. It is nothing but a waste of time to try to be someone else's best. Take inspiration and guidance through comparison, but do not make value judgments from such comparisons!