Playing when tired vs. experience gained from 4k hands....

Just finished 4k hands; I made a few mistakes due to being tired and unfocused. It's obviously not profitable in real terms to play when feeling like this, but I'd still rather play than not. The reason is that I think 4k extra hands experience will add profit in the long run. I think I left about $20 - $30 in the middle tonight due to taking spewey lines or making hero calls where the calling price was clearly wrong. Never the less I think I learned enough to compensate for this and in the end I didn't lose any money on the evening so I won't complain too much. One thing I've noticed is that when I make mistakes I get annoyed and end up playing a more aggressive style. I don't think I start to make ridiculous plays but in those spots where I'd be like: 'well I think he's bluffing but I'll let him have it'; instead I'll have the attitude: 'you are so full of crap and this pot is MIIIIINNNNEEE.'. It's suprising how often my redline rockets when I'm in that kind of mood lol. (EDIT: Tilt is not profitable!) Anyway, what's clear is that I still have a large number of leaks that need work.
Expected Value and Betting
I heard the great Brian Townsend discussing four bets the other night and it got me thinking. The main point was that we can make a play with a made hand that is still profitable despite that we're never called by worse. Basically this defines 'turning a hand into a bluff'. When we four bet someone who is 3-betting liberally then we are turning our hand into a bluff if we do not stand to get called by weaker hands. For example if we four bet TT. The reason aggressive play like this is profitable is that people fold too much. This is the only justification for turning any hand into a bluff. I didn't explain any of that very well, but I may spend a few days with the EV tools I have and clarify my understanding of a few points. I feel like I'm so close to understanding poker equities and their relation to betting.
Not resting on One's laurels
OK, so while I may be close to getting the EV side of poker, there's still a load of strategy advice that I need to digest. So I'm going to make a point of:
1/ Reading as much as I can on 2+2
2/ Watching as many Cardrunners vids as I can fit into my spare time
3/ Doing much more analysis using pokerazor/stoxEV or other similar tools
The road to good play is a long one, but with my maths background I don't feel that there are any great pitfalls ahead; my only enemy is complacency.