Another computer dummy question - how delicate are CPUs?

[frosty]

I finally got a new--but used--desktop to replace my ancient Compaq PIII. The specs for this system:

-Pentium 4 3.2Ghz
-Intel 945G-M3 motherboard
-1 GB DDR2 memory
-Maxtor 160GB SATA II hard drive
-Sony DVD-RW

everything is still newish (three months old, seller tells me), but the thing that got me sold...black case with clear side (and small clear top) panel with blue LED lights. The front has two clear tube-like thing on either side that lights up blue also (can be turned on and off). The price? Seller wanted $285, but I got it down to $275 (originally asked for $260). So, I must still ask, did I get a good deal?

Okay, when I got it home I decided to remove the huge CPU heatsink and fan. There was some very sticky greyish goo on the part of the heatsink that makes contact with the CPU. What is this goo for? Then curiosity got the best of me and I decided to remove the CPU, and as I did I got a miniscule smudge of goo on the underside of the CPU. I believe two of the circular connector points got touched, so I delicately used a napkin and wiped it off. Did I do anything that may affect the CPU performance? It turned on fine after I put everything back, but I need some confirmation. I should have known better than to mess with anything inside.