Following my piece from last week, on Will Baker's super chub, my own mind has been buzzing. For one reason or another, I've been on the waterside pretty well every day since guiding, filming, photographing or just plain fishing and I've seen so much to back up what I wrote about last week.

Let's look at the last few days in more detail and see how they have reinforced my ever-growing belief that we know next to nothing about the big, wild fish we pursue.

First off, I'm guiding on Friday, on a particularly prolific chub stretch. I get on there in the early morning and I see chub at every twist and turn. I guess in the early morning light, I probably count anything up to 200 fish with one or two of a size that is quite eye-watering. I'm agog with excitement and I tell my guys all about it over breakfast.

We eventually arrive in the mid-morning with the sun well up. The light is perfect and the river's clarity is good. At the first bend, I creep up with supreme confidence and see... nothing. It's the same on every curve of the river.

We did winkle out one or two during the course of the day, but I'm constantly aware that they are mulling over my earlier stories with scepticism. It's heartbreaking for me. How do I convince them a stretch of river is full of chub when, now, even to me it looks next to fishless?

Saturday I take the same team to a Wensum gravel pit that has some spectacular, legendary, veteran carp in it. It's barely ever fished and you'd think that we'd stand a chance given the fact that the water lies fallow for so much of the year.

However, we come away fishless. We have one or two half-hearted pick-ups and perhaps a near chance off the top, but it's like those carp simply know exactly what we're at. Of course, they've been fished for in the past, probably by better carp anglers than we are, and they know exactly what the game is all about.

Those scientists that say fish have memory spans of three seconds really should be with me now. Those carp, those magnificent leviathans of fish, are really ahead of us today. I don't think the guys mind too much this time. After all, they can see the fish and there is, therefore, no doubt I've taken them to a hot spot. If you can't catch, ultimately that's down to you.

On Sunday, I'm doing some perch fishing because I need some underwater footage for the Mr Crabtree films. The idea is that I catch my fish, phone James the cameraman and he comes out immediately to shoot some underwater release footage. He lives only five miles from the water so the fish will only be sacked for a matter of 155 minutes or so, a justifiable exercise, I think. I'm fishing where I know there are some big perch, under the tangled roots of some alder trees. I've had them here before in the past and I think this is the problem today. The perch are here, but they're not having maggots, worms or even dead baits. Perhaps it's too bright, perhaps the water is too clear and perhaps they've just seen all my tricks before. As it is, I hook one of around two-and-a-half pounds briefly, but I guess the bait wasn't taken properly. Two head bangs and the hook was out. I stood James down.

On Monday, I'm out guiding again with a good fisherman and a guy who reckons he knows chub. We fish a prime stretch and manage to winkle out one fish of around five, but the guy thinks that there aren't many fish on the ground.

The following day, I meet up with the excellent Environment Agency Fisheries team who happen to be electro-fishing that very beat of river. It's heaving with chub. I've forgotten the figures but they probably take over 20 to nearly six pounds in weight. And we're only talking about a stretch of water some 200 yards long. How come my guest and I could get it so completely wrong?

On the Wednesday, I meet up with Karen Twine from the Environment Agency Fisheries Department.

Karen is based further west and has recently completed a PhD on barbel. It's refreshing to find someone who appreciates fish for what they are, objects of supreme natural historical interest. It's also fascinating to talk to her about exactly what I've been experiencing over the last few days.

Over and over, she tells me, she talks to anglers who lament there are no barbel left in this or that stretch of river. However, she can pick up endless individuals that she has radio-tagged over the past year or so. Those fish are still alive, well and travelling the river, under the radar of even some excellent barbel anglers.

We think we know so much about our fish and our fisheries – I've certainly been as cocksure as anyone over the years. Yet, in the final analysis, there are so many older, wiser, spookier fish that seem to be almost light years ahead of us.