"Harry, I'm going to let you in on a little secret. Every day, once a day, give yourself a present. Don't plan it, don't wait for it, just let it happen. Could be a new shirt at the men's store, a catnap in your office chair, or two cups of good, hot, black coffee. Like this."  -Dale Cooper

I was going to say that I found the "haloperidol fog" theory inadequate, since by the time of his last scene with Cooper he's definitely aware of Laura without them telling him about her.

But then, by that last scene, it almost seems as though he knows who the killer is anyway, and Cooper is trying to find the path to knowledge, not the knowledge itself. So on that count I guess it still sort of works...

I'd like a better one, though.

"Harry, I'm going to let you in on a little secret. Every day, once a day, give yourself a present. Don't plan it, don't wait for it, just let it happen. Could be a new shirt at the men's store, a catnap in your office chair, or two cups of good, hot, black coffee. Like this."  -Dale Cooper

Is it possible that he only knows it's Leland when he's in the presence of Leland? I'm not sure how reliably consistent Gerard is as a "conduit" for Mike, especially given that he's on the drug. There may be some static on his channel. And Mike may not be too trusting of Cooper, for reasons that become clear in the final episode.

Another thought: Is time linear for Mike? 

"Harry, I'm going to let you in on a little secret. Every day, once a day, give yourself a present. Don't plan it, don't wait for it, just let it happen. Could be a new shirt at the men's store, a catnap in your office chair, or two cups of good, hot, black coffee. Like this."  -Dale Cooper

"There is no need for medicine. I am not in pain."

Is it possible that he only knows it's Leland when he's in the presence of Leland?

That could be it, and the fact that he's wearing the owl cave /Black Lodge ring when he sees Leland. I can't recall him wearing the ring any other time.

Why is it that Mike doesn't change hosts?  Why does he have the same face in and out of the lodge?  That bugs me!

 But back to the original question, Mike specifically says "It's your father!" in the "traffic scene".  Why wasn't he taking his medication?  Seems to me that if he didn't, he wopuld be laid up in bed with a wet rag on his sweaty forhead...right?

That bugs me too.  Mike obviously loves the heck out of his original host whereas Bob is a host whore

Maybe that's what attributed to Mike's piss poor driving skills in FWWM, he was off the meds

Also, what is the backstory of Bob's original host?  Was he a homeless drifter? His TP card says he has been around since the beginning of time

"Harry, I'm going to let you in on a little secret. Every day, once a day, give yourself a present. Don't plan it, don't wait for it, just let it happen. Could be a new shirt at the men's store, a catnap in your office chair, or two cups of good, hot, black coffee. Like this."  -Dale Cooper

FWWM is a sort of a sequel, thus Phillip Jeffries (WHO DO YOU THINK THIS IS THERE?), Cooper in the lodge but not aged, Mike knowing the killer's identity, and Annie appearing in Laura's dream. My idea is that since Cooper is now in the lodge, he's in there for all time. This type of intervention would cause events to move along differently during the Theresa Banks investigation and Laura's last week, perhaps even in our entire known universe.

I'm of the opinion that we'll never see the last seven days for Laura as they occurred before the events of the pilot.

The who MIKE/Philip Gerard thing has always been an sore point to me. What does MIKE really look like ?

It's extremely unlikely he found a host who looks exactly like him, but apparently he did, if you believe the show.BOB never looks like his human host, yet MIKE always does.Kinda weird, Huh?

Also, there is no need for medicine, er, I mean there is no need for MIKE to discard Philip Gerard as his host, since Philip Gerard was never put in a position of being locked up, like Leland was.

Philip Gerard can "turn into" Mike by not taking drugs yet Leland never had that problem of needing drugs to stay Leland.

There are a lot of these inconsistencies that us fans try to explain away but the fact is the writers were pretty much making this stuff up as they went along and in a show this complex that can lead to problems that fans who keep track of everything are aware of.

"Harry, I'm going to let you in on a little secret. Every day, once a day, give yourself a present. Don't plan it, don't wait for it, just let it happen. Could be a new shirt at the men's store, a catnap in your office chair, or two cups of good, hot, black coffee. Like this."  -Dale Cooper

Leland doesn't need drugs to stay Leland because BOB takes over when he's supposed to be asleep.

Plus I don't think the viewers have ever seen Phillip Gerard under the pretense that it's Mike's true form (by the way, what's with the capitalization? I suppose a good excuse would be to distinguish the two Mikes, but at the same time as a commonality with BOB that would be incorrect. BOB actually does stand for something. Plus to add to that, who actually talks about Mike Nelson anyway except for in topics such as "Worst characters?" Tangent Ahoy!)

Mike is different from BOB, though, in two key, related ways. First, he's apparently rejected the "evil" path and is trying to stop BOB from continuing down it. Second, he disfigured himself ritually in a major way in order to make it official.

Perhaps due to the moral restrictions implied by the first, or some technical aspect of possession that inspired the second, Mike can't leave Gerard. And this would be why Gerard has to take the drugs he's on to keep Mike subdued, while those inhabited by BOB seems to have perfectly normal periods without medication (when BOB is presumably absent, possibly wreaking havoc through another host).