Being able to play by ear is a very useful gift. However, if you can hear what you want to play in advance, then be able to hit the notes perfectly every time, in any key over any chord, you're laughing.
Understanding music is like understanding a new language - you can learn a few phrases that'l get you by, but in order to hold a proper conversation, you need to know how to speak it.
Also, it's not as hard as it looks, and you may find it throws up some unexpected and intriguing new ideas.
Don't aim to be like Slash - be better.