Here's how not to be a choosing beggar, as illustrated by one mom who couldn't accept a good thing while she had it. As a child, getting to bounce on a trampoline is basically the best thing ever. It never gets old! If you go to a trampoline park, you and your friends can literally bounce off the walls (and all over the rest of the room). Having a trampoline at your house is the ideal scenario for kids, though. It means that you can run outside at any time and start jumping. You make up games a…