Not for me. I research everything. Right now, I want a 1911 in .45acp, an AR-15, a 22lr pistol, and something ultra accurate in .308, and a 12ga shotgun. I will get each one of them. Probably a RIA 1911, a Browning Buckmark pistol, a kit from Delton to build out my Spikes receiver, a DPMS LR308, and a mossberg 500. As I get the funds for each one, I'll buy them. That is pretty calculated.
Previously, I knew I wanted an AK, so I built three. You don't build three on an impulse.
The last two times I was in the gun shop, though, there were guys in there buying guns that were CLEARLY impulse buys.