Farage is a flea on the rump of the political horse. He isn't interested in the hard grind of day to day political work, He just enjoys nipping the horse and making it squirm.
He founded UKIP, which only functioned while he was in charge. Every time he got bored and tried to move on, it collapsed. In the end he got terminally bored with it and left it to decline into the rather nasty rightwing deflated balloon it is now and founded a new party. Which left him in a dilemma.
There is a chance that the Brexit party could win a seat in the coming election and he would be expected to stand for a seat where he could end up an MP and that is the last thing he wants.
Its the being in the public eye and being considered important and fawned on by the likes of Trump that matters to him, the last thing he wants to do is become an MP and be judged on his -in-capacity to get down to the hard work, and it is hard work, no matter what people say, of being a constituency MP.