I'm still relatively new at being a rail enthusiast - I've been going "seriously" for just over a year now - and already I have quite a few regrets, mostly from being a few years too late for various things - the Oldham Loop Line as heavy rail, A stock (though I travelled on this quite a bit when I was much younger), Valenta engines (would you believe I don't think I've ever heard one, at least knowingly, in person?) and a few others spring to mind.
Most people in the country have heard one at some point in their childhood (depending on age obviously!), even if they don't know what it was at the time. I sure didn't at the time, but you don't forget the sound of a pair of 'proper' HST power cars on an 8-coach set screaming by you at 125mph through Slough. Amplified by the footbridge directly above where I was sat at the time on platform 2. Shame I was quite young at the time, but this was when the Fag Packet livery was the king on the Western and no sign of the Barbie livery for some time to come.
Oldham line when it was heavy rail? You missed jack squat, it was dull and in dire need of modernising when I did it years before the Metrolink conversion was to begin. TV screens were still on the entrances to platform 2 telling me the Pacer was going to Shaw and Compton!
As for the 'A' stock, meh I really didn't care for that. But then I much prefer the 'C' stock. Admittedly the 'S' stock is a lot better for various things including air conditioning, something I bet every Tube user was glad of last summer!
I've noticed a few people have mentioned record keeping - I'm taking photos of everything at the moment, with a reasonably decent camera, but what records would you recommend I take and how, to avoid having similar regrets myself later? I've mostly been restricting record keeping to recording unit/loco numbers for trains I travel on, which stations between and WTT timings as well as actual timings, as well as headcodes and route if there is more than one/if it's odd for any reason, as well as platform numbers at origin and destination. Should I be recording more (ie an exact breakdown of which lines/platforms were travelled on throughout the whole route)?
What records you keep and what you don't keep are entirely up to you, but to note things like whether you used the Down Slow Maidenhead to Reading platform 9 (I think this used to be 8 pre-remodelling) then crossed to the Down Fast from there to Didcot Parkway platform 1 might be excessive. That level of detail on a lengthy journey (say Euston to Glasgow Central) could take some doing! Below is what a typical journey would look like on one of my bashes, data is randomised for the example:
170503, in 79503, Hereford -> Birmingham New Street(p10b)(via Worcester Shrub Hill) (0849,1d,arr 1018,5u)
If the journey was taking an unusual route, I'd make a note of it in the same brackets as the 'via' bit in this entry. I'm going to mention that entry is impossible to fit on one line of a standard notebook without a lot of abbreviating!
Pre-RailMiles, I'd not note the arrival time, only the departure time and any delay). There was also a time I didn't even note the departure time, so an entry in my notebook at that point would look like this:
158850 Newport to Hereford
A fair bit of a difference in the detail, and for the first couple of years or so I didn't usually write it all down, I'd mark trains off in my Platform 5 book (yes I was once rich enough for one of those!) and that was it. That is one of the errors in record keeping I seriously regret.