1) The Mishna Berura continues and mentions another few items that are “koshe lishikcha”- that cause one to forget their learning. One who puts on two garments at one time is koshe lishikcha.
2) One who reads the writing on a grave is also koshe lishikcha. Many poskim write that if the writing is engraved into the stone it would not be an issue. Furthermore, the custom of placing a stone on a grave when visiting it, also helps regarding this matter. Certainly if both factors are present, the writing is engraved and one leaves a stone it would not be an issue to read the inscription.