This has been busted for like 5 years. When it happened, they said they were gonna fix it.
If you play with smart+self cast (which I do) if you don't have a target under your mouse when you smart cast something that can target allies or yourself, it targets your champion.
Morgana shield is a good example. If I just press E with no target, I instantly get a self-shield.
Basically any champ with an ability that can target self works this way. All of them, in fact.
All of them except lee sin.
If you're lee sin, you have to hover over yourself, or the ability simply just doesn't cast at all.
When you've spent 10 years playing this game with this control scheme, you get used to and expect a certain behavior -- its very hard to re-train yourself to hold ALT or hover over your champ, or whatever -- especially when this action isn't required on anyone else.
So i'm just wondering why Lee Sin is the exception, and why this was never fixed when we were explicitly told it would be?