When you "push" film, it's left in the developer for longer than the normal amount of processing time. The result is an image that, although now correctly exposed and processed, has much more contrast and grain. This is done for several reasons - not the least of which is the reason you stated...it was the only film you had with you and you needed something faster for the subject at hand. Some people like the super-high contrast and grain (although to me, these look like a first year photo student's attempt at an "artistic" experiment....but that's just me (please people, no hitting)). I used to shoot high school football games for the local paper here, and I would shoot T-Max 3200 rated at roughly 25,000 (1/500sec @ f5.6 at night with high-school field lighting). I'd process the film for about 20 minutes in T-Max developer - and it actually looked pretty decent (looked a lot better than attempts with a flash, in my opinion). Anyhoo - hope this helps.