[Nsight7]

It is and it isn't rocket science, depending upon who you are playing of course. I mean if you are playing high stakes then you are going to opt for optimal play, and that can be very difficult to do. Some people seem to have a natural mind for it, and for others it must take a lot of work.

In most cases though, we utilize exploitative play, wherein we exploit the errors of weak players. So basically, like everyone else said, practice good table selection, because it is simply easier to play ABC-TAG than optimal LAG. When playing optimal you are prepared to sit at nearly any table I think as well (though you certainly should prefer certain tables over others). If playing ABC-TAG, you really are looking for specific tables and sometimes profit opportunities are harder to find.

And I am with you, right now I am a bit depressed and my game isn't actually doing great, as I am in the worst slump I have been in in half a year. Just play through and adjust if possible, and exploit.