2. Power game. Build that character who's tricked out and can one shot an enemy 3 levels higher than him. Playing with the system and figuring out its loopholes and limits will give you a deeper appreciation for everything mechanical that you can do with your game.
3. Play an indie game. There's a large number of games out there that stretch our imaginations as well as our definition of "roleplay game". Maybe you've always wanted to play something that doesn't require lots of DM prep time to build encounters. Might I recommend Don't Rest Your Head? How about a character growth intensive game? Primetime Adventures could be for you.
4. Game Master. At worst, doing this once might make you more empathetic the next time your GM doesn't recall a rule or forgets an NPC's name, and at best you might find that you love crafting stories, world building, and playing 50 characters instead of just one.
5. Play your weakness. Build a character with a significant weakness or phobia, and play it up. Maybe your character is low in charisma or manipulation on the character sheet. That doesn't mean he'd never try to tell a lie. Play it up, but rp how horrible he might be at it. This can be fun, and get you to care less about failing rolls.