This looks like an awkward question. We will confess that he/she is not lovable? But the truth is that many of us are not lovable at all. Can you imagine of a small kid? A kid is always lovable. Why? If we can answer that question, we will solve the puzzle about whether we are lovable or not.
A kid is innocent. Knows nothing and is totally defenseless. You love a kid, because he/ she wants you to protect him/her. You love a kid because of innocence. You love the kid because of the smiling face. You love the kid because the kid has no malice towards anyone. Does not desire any thing bad for any one. Recognizes no enemies and has faith in everyone. The kid is totally free of all negative emotions. That is why we all love a kid.
How many of us are like that? How many of us keep a smile on our face forever? How many of us are free of negative emotions? Not many. Agreed that we are grown ups and can not be like a kid. But surely we can borrow some good qualities from the kid. How about forgiving everyone? How about not getting angry at all? How about having faith in everyone unless proven otherwise? How about loving everyone? How about becoming non judgmental?
Once we acquire some of these qualities, we will become lovable. Believe me that it is that simple. All of your friends and colleagues will begin liking you more. You will get love from unexpected quarters. You will get your dream darling in a little time, after you transform yourself.