Remember that you aren't moved automatically. You have to do that. The tutorial shows you this.

For every 1 sphere grid level, you can move forwards one node (the circle things. like the ones that have str+1, hp+200 or spells like haste) You can move backwards four nodes.

Since Cheer is two nodes in, but you only have to be *Next* to a node to activate it, tidus only needs 1 sl to be able to use an ability sphere to learn it.

Haste requires 11 sphere levels. It's really best if you move them, so everytime you get one, advance to the next node if you've activated all the ones you're able.