The loudest boos come from the cheapest seats. Think about all the people you associate with who are in the crowd but not necessarily in YOUR audience. They pick apart everything you do...  They're the first ones to boo you... never come with the  positive.... always on the negative ESPECIALLY when you step on that stage (whatever YOUR stage may be)  They're just up there in the nose bleed section miserable... and because misery loves company, they want you to be miserable too. They boo you because they can't be you. And quite honestly they would much rather be on that stage or at least court side than having to watch from the cheap seats. 

Don't let them boos distract you!