I thought I'd share an experience that I have just had.
I settled down to do my normal mindfulness meditation. When I meditate I usually experience a definite moment; a point in time before which my mind has the usual chatter and after which my mind is still enough that I can concentrate on my breathing without mental perturbation. It is after this moment that I have often felt 'physical' sensations of pleasure. All angst seems to drop away and it happens suddenly (all the while I try not to become fixated or attached to that mental state and continue focusing on my breathing). I usually meditate in 30 minute slots; I'm usually too busy to commit more time. I use a discreet alarm to inform me when the 30 minutes is up.
In my past experiences I have always felt as though that moment in time, described above, happens right near the end of the 30 minute sitting with perhaps 5 minutes or so to maintain the focus before the alarm sounds. Obviously I have no way of knowing how long for sure it would usually take. Today was no exception. I passed that moment in time and continued and, on reflection, it felt like 25 minutes or so had passed. Just then, my phone loudly and obnoxiously rang. I usually put it on silent mode but had forgotten. The sudden loud noise startled me. When I looked at the clock, just 15 minutes had passed since I started the sitting.
What this suggests to me is that the early period of my sitting seems to drag, feeling like it is taking far longer than it really is (perhaps twice as long), yet the latter period of my sitting flies by in what seems like just moments. Presumably I'm not breathing more slowly, and I'm still being mindful of the breathing (but without numerically counting the breaths at that stage). Certainly I do not fall asleep, yet the time in the latter part of my sitting seems to progress far quicker than the early part.
Had I not received the phone call, I'd not have found this out. There isn't really anything I can do with the information. It doesn't affect anything and I don't really need advice about it. I just thought I'd share.