I believe the fellow who told you that was passing along an old wive's tale. There is a lot of nonsense floating around about gasoline (high octane burns hotter, it has more "power", etc).
The only real difference between lower and higher octane is its tendency to predetonation. That is, at high compression, higher octane is more likely to wait for the plug to spark before it starts burning, whereas lower octane may ignite under compression all by itself. (This is bad... it's called "knock" and puts a lot of stress on your engine, not to mention not pushing you forward the way it's supposed to.) That's why high octane is important for engines with very high compression ratios, and the reason the "more power" myth is so enduring. (High compression engines being higher performance, so obviously they need "more powerful" gasoline, right?)
If your ped generally runs okay on regular gasoline, then the only time you may notice a difference is if under extreme load (struggling up a steep hill, perhaps) your engine knocks. If so, you should definitely go with higher octane, since even an occasional knock is very hard on your engine.
I personally just ignore all that stuff and put in the highest octane available, with attention to make sure it's not a gasohol blend. (You definitely want all-petroleum gas). Since I have a 1 gallon tank, I generally add fuel 1/2 gallon at a time, so I can easily mix the oil correctly. The difference between spending 49 cents and maybe 53 cents on a visit to the gas station is, IMO, not worth worrying about.
Just my two (or four? <g>) cents...