I'm assuming you mean me, Sp00n?
If it's a long-haul flight I find that I'm suffering if I don't get to sleep whilst in the air. Otherwise my body clock seems to take an age to adjust itself and I don't really get my act together as a result. The last time I flew long-haul, which was a while ago, I had a day in bed at the other end as I felt like death warmed up and was staggering around like an over-enthusiastic extra from a zombie movie.
Sadly this all stems from a childhood/young-adulthood of thinking that having your own little comfy space on a flight, be that a whopping great reclining armchair or your own little 'pod', is totally normal. I have to be very, very tired to sleep in the type of seating you get in Economy or pop some sleeping tablets to knock myself out.
Looking back, I wouldn't change my childhood flying experiences for the world and I consider myself to have been incredibly lucky to have flown where I did, how I did. But it's certainly costing me now!